An important point from the discussion today I'd like to highlight is that 'objective ethics' is a contradiction.
There are some systems of beleif that might argue that there is such a thing as objective ethics. For example, religions would assert a set of moral truths - "thou shalt" - which are universally or objectively (ie: true independantly of subjective construction or judgement) true because God/s said they are. And that the set of moral truths constitute an objectively true system of ethics. Alternatively a scientific or sociological approach might investigate the frequency of actual morals and moral principles across society. It might turn out that all cultures or persons hold one or more moral principles/imperatives in common, and that these may be regarded as objective moral standards. Or there might be statistically frequent ones, with confidence intervals etc which are more or less 'objectively true' prima facie from an empirical science point of view. Again these may be regarded as constituting an objective ethical system.
First lets consider terminology. I'll use philosophical definitions, rather than laymans terms, since we are philosophers (In laymans terms 'ethics' and 'morality' are little distinguished. Regardless of terminology, the distinctions are useful for our understanding of stuff). A moral is a 'should'. A moral statement is an assertion that we should behave some way as opposed to a statement that we do behave some way. Morals always involve a choice.
An ethical relation is one in which two or more 'subjects', capable of making choices, can make moral judgements of one another, ie: you should have done x, you should not have done y; it was wrong to do x; you are right; all people at all times should do x but you did y so you are evil... This might also be extended to other judgements, like you are beautiful, but lets stick with morals right now, since most people think of ethics as being about morality.
So it is 'unethical' to treat another 'subject' (like a person) as an 'object' (like a stone, or a tool, only). It is ethical when dealing with subjects to recognise that they are capable of constructing the world in their own way, their own opinions about reality, capable of making their own moral judgements, and their own moral judgements of your actions - and importantly, that they do so independantly of you. You never really know what another person is thinking, etc. In an ethical relationship you recognise that someone is like yourself, capable of perceiving and acting in the world, and of judgement, yet they are not yourself, and you cannot understand them in the sufficiently complete way you would understand a 'thing' or object (like a rock or shovel - whether animals can be subjects or to what extent, is debatable).
So then you have the morality of ethical relationships - what should we do to each other. I should treat people well. You should not treat people like objects. You should not treat me like that. You should use rocks this way, not like that. Everyone should obey the law. And so on.
But the point is, that ethics involves 'subjects'. And the distinctively ethical point about this relationship between subjects is that they are each capable of their own judgement. Because it is a matter of subjective judgement it is necessarily not objective.
This does not in any way devalue ethics or morality as a 'meaningless relativism'. Rather it compels us to acknowledge and respect each other and ourselves as arbiters, as judges. We cannot simply say "You're wrong acording to this book of objective morality here so I'll chop off your head". We cannot act lightly without considering the consequences of our actions. We can't assume what other people think without asking them. It compels us to negotiate instead of force, or at least to accept that to force is our own decision and judgeable by others.
It also is not 'meaningless relativism' in that we can talk to each other, and decide, for example that everyone should have a right to walk down the street without being murdered, so lets make a law saying murder is wrong. I wouldn't like to be murdered would you? And lets say, anyone who murders will be locked up by these other people who have decided to follow that through. We can establish moral principles. We can and do agree on them and fight about them. They are not meaningless at all. Because they are intersubjective, not objective, does not make them meaningless or any less important, quite the contrary - it gives each of us and our moral decisions more meaning that we could possibly have if morals were not our choice.
Each of us must say, "I am the arbiter of right and wrong."And each of us must recognise that each other person is too.This gives us enourmous freedom and responsibility.To say "I am the arbiter of right and wrong." is not to say "Yippee I can do whatever I want." On the contrary it makes us weigh our thoughts and deeds with gravity.
It can be hard and conscience wracking to figure out what is the right thing to do, or if we should care at all. But luckily we are equipped with reason so we can figure it out. Ultimately we can say we made the right choice at the time, given the information, no regrets - but only if we accept the freedom/responsibility of being a moral and ethical creature. It is typically when people give themselves over to an 'objective morality' that atrocities are committed.
One of the reasons religion is appealing to people is because it is hard to figure out what is right and wrong. (Notably many people who turn to religion are people who have really stuffed up their choices in life and have become desperate.) Life becomes easier if someone else tells you.
But I reckon that's a bit of a weak way to be a person (Blessed are the meek!). It is to relinquish what it is that makes you a person - your ability to judge and to choose. (Worth noting here also, that religious beleif depends on faith, not reason which is what we need for judgement).
I must acknowledge that I get a lot of this thinking from Emmanual Levinas - and also that this breif discussion doesn't nearly do him justice. I reckon no philosopher ought to be comfortable talking about ethics unless they have read Levinas' Totality And Infinity - so read it. On reading it - I have to say I didn't understand a single thing he said for 6 pages. Then when I finally did it was like a revelation and I understood what he was saying for those six pages. So - it's a difficult read at first, and it would be good to have a teacher, I beleive Chris Falzon knows Levinas, but once you get into it it is beautiful and thoroughly rewarding. I was almost religious about this book for a while.
On that note - I have no objection to philosophy being personal. Why do philosophy if it isn't relevant to you? Considering the discussion today, I'd like to add that reading Levinas was a significant factor in my decision not to abort the first 'accident' my wife and I had. It has affected my thinking ever since and been a good basis for deciding about how to relate to my children. They are like me, I will teach them, but they are not me, they are subjects and form their own judgements etc. The way Levinas describes love, fecundity, old age and children certainly provides an a-religious conciliation with death.
So when my daughter beleived in God for about a year or so, it was not vitally important to convince her otherwise. I never beleived that her beleifs could be controlled absolutely by me, nor the scripture teacher. And I was ready to accept it if she decided to remain a Christian. I was always honest with her about my own beleifs, which are very hard to explain to a 5 to 6 year old, but I did what I could to explain if she asked. One day she said "Now I beleive in God about a quarter." and that was all her figuring out - even at 6 years old. I never told her not to beleive in God. I didn't even say I didn't beleive in God. But that said, ours is not a religious household.
When there is no objectivity, no absolute truth, independant of us, what matters above all is honesty.