[pook]

Everyone has great advice.

I recommend learning a language or 5. Ocaml, Erlang, Lojban, Japanese, Quenya, etc. Use Mnemosyne and Smart.fm for quick, cumulative study sessions, translate webcomics and such, play golf with old programs in new and differently powerful languages.

Also, read more. You'd be amazed at how many great SF novels you can read in a year, or how quickly you can devour Misner's Gravitation at a few pages a day.

I think the overwhelming point of all this advice is to have fun. Do things that induce flow.