Driving games are where it's at on the PSP. While most other PS2 ports feel cheap and limited on Sony's handheld, the driving games on the system tend to make the leap pretty well, so long as the developers are able to deal with the finicky PSP analog nub.
MotoGP is a fine example of this - a great little racing game on your little PlayStation. The licensed tracks, the licensed drivers, the real bikes and the sense of speed are all here. And though the control isn't quite as precise as what we've come to expect with the console versions (say goodbye to separate front and rear brakes), it still delivers well enough to make for an enjoyable experience.
You'll stay busy, too, with a handful of different game modes to conquer. Along with the season mode (where you can race multiple seasons in an attempt to climb the ranks), MotoGP includes time trial, specific challenges for unlockable content, wireless multiplayer (though you can't race online) and one-on-one races with real MotoGP drivers from the 2005 season.
There are limitations, though. In particular, the season mode could have been a lot better with a few tweaks. As it stands, you begin your season with whatever team will sign you (no top-tier teams), and then run every track. At the end of the season, you can re-sign with your team (assuming they still want you) or move to another one.