i got a PSP when they first came out which was....however long ago, anyway i went through a patch of not picking it up for 6 months but i still pick it up now and play on it! the games are limited, hardly anyone seems to make em now. i take it on holiday, use it on the long flights and the mrs got me a speaker set to go with it so we use that instead of a stereo when we go away.
It really depends on what you want it for, if its hours of gaming then 1 your battery will die and 2 you'll have such bad crab hand you'll wish you'd never bought it. But if its more of something to take away with you listen to some music, watch a umd and play games on every now and again on then get one!
(But saying all that, i have a NDS on its way from amazon!!!)