On the rare ocassions that I have used a true limo - my kids proms or my daughter's wedding - I have tipped the driver because he's made the Event (even more) special in someway or because it's been a lovely day and I wanted to share the joy a little. Not because I felt that, on top of the already high price, I should payout some more money.

In the case of "airport limos" those vans that are not at all luxurious and drivers who get me there (although why they take the longest possible route from the airport to my house when I just want to get home, I'll never know!) There is really no way I'm tipping those guys.

DD: This might sound weird, but I've never been in a limo.