I don't yet. I've asked around on air about this very subject and for most part all seem to agree that doing QSL cards for local contacts would be bad form. When it comes to remote contacts, like over Echolink or IRLP it depends upon the specific situation and the people involved. If you get into longer distance conversations via sporadic e or bouncing your signal off satallites or the moon, then QSL cards are very appropriate.
It is my sense that most would consider using the internet to make long distance contacts to be "cheating" - but even with that said just this morning I helped a local ham get the address of a spanish speaking gentleman he was having a QSO with in Costa Rica so that a QSL card could be sent.
On the subject of QSL, you can do it over the internet and save a bundle on postage but won't it be cool to know that a QSL card with your Land Cruiser adorns walls all over the world?
Ricardo Maestas - Bio Page
1999 LX 470, 1971 FJ-40