(You don't want to let anybody else use your browser profile. Especially with all those "smart" address bars. Rather set up a guest account and switch to it. It

(You don't want to let anybody else use your browser profile. Especially with all those "smart" address bars. Rather set up a guest account and switch to it. It's also very useful for presentations. Recent Linux distros makes user switching very easy and reliable, so it's worth doing even for a very short sessions.)