Saw this on digg or something last week (and a friend also sent it to me via del.icio.us):
10 Linux Shell Tricks You Don’t Already Know. Really, we swear
I usually don't find these posts very useful, but this one had a couple of nice surprises. I'd never heard of ssh-copy-id, but it sure looks a lot easier than adding pubkeys manually. And the trick of recovering from an NFS mount gone haywire might work for a Samba mount (that happened to me the other day).