Apart of being against company rules, I wouldn't like being tipped at all. I don't consider myself a waiter, and I suppose that if people don't tip FA it is because they don't either.
In 11 years it only happened to me a couple of times with elderly people, and once with a pax whom I helped to get un upgrade (which he deserved, without getting into details). Especially with the last one, I think it would have been very unprofessional to accept a tip (it was like 50$), because in that situation it could have looked like a "payment" for my help to get the upgrade.
Of course you have to find a very polite and friendly way to refuse. In all cases I told them that it had been my duty and my pleasure to help them and make their time on board enjoyable.
[ 03 September 2001: Message edited by: flyblue ]