I think its worth it. If you've got a wireless connection in your house, that's also a plus. PSP can play homebrews (like old NES games, roms, etc) if you've downgraded to 1.5. You can put wallpapers which is a nice feature, as it makes your PSP unique (iPod guys have to hack the firmware
)
The fact that there are man games you can play on WiFi vs another person with a PSP is a nice touch. I'd recommend looking into the game 'Ridge Racer', its quite fun and entertaining.