iPod is a great choice, as would be new CDs or a new mobile phone.
That is, if I personally had about that much. I recently got my mobile phone locked trying to change my PIN number to 2112 (yes, I know

), and it's really old anyway... the screen itself was primitive when the Game Boy was a new product. But yeah, you probably wouldn't want that. Can't go wrong with CDs or an MP3 player of some variety, though. An external hard drive or something if you need one.
I wouldn't advise trying to spend it all in one place though. It's nice to have it there, in case you need it.
Jam it back in, in the dark.