I use the safe-rm (http://freshmeat.net/projects/safe-rm) package to help me avoid doing this kind of thing.
Eg:
rm /whatever -rf
Ie, if you hit enter too early, you still haven't forced.
I've been using Linux for 14 years and have never accidentally rm'd recursively. I'm not sure when they added it, but I've been using it for a very long time.