1. @ — Email saved this one. I still see it as representing the word "asshole."
2. # — Resurrected by Twitter. In particular, annoying Twitter users who think they know how to use it but don't.
3. & — Just go out and say the word "and," you lazy bastard. Using the symbol only saves you one keystroke.
4. ^ — This arrow is simply fodder for emoticons. It exists for no other reason.
5. % — Totally outmoded by the decimal system.