Thanks DJ! We thought long and hard about the best way we think to handle TKs. We use statsme as many of you may know, and there's a little add-on called [ATAC] (Advanced Team Attack Control) found on olo's statsme page http://olo.counter-strike.pl/. It plugs right into statsme, and all it takes is some clever .cfg file editing to disable the punish options on the menu, leaving only forgive. If someone kills 3 times without being forgiven they get kicked.
Now there's no way to get rid of the menu normally, so if you don't want to forgive you have to wait until next round and use a radio command or something to clear the menu out.
ALSO:
You have to be sure to have mp_tkpunish set to 0 in your server.cfg so it won't kill the attacker on the next round automatically.