I'm a sucker for a good arcade racer, so I downloaded the Gravel demo from PSN to give it a shot and it's pretty fun. The graphics aren't great, but they're good enough. You can only race on one track, with two layouts, but it gives you a decent feel for the game. I wouldn't pay the full price ($50) for it, but I'll definitely grab this when it goes on sale for $20 or less.
You can get a good look at the other tracks here (you should probably mute the asswipe talking):
Price dropped to $24.99 and I have a $10 PSN credit, so I'm thinking of getting it now.