Looking for a good time-waster? Check out Adrenaline Pool Online for the iPhone/iPod Touch. It’s just $4.99, easy to pick up, and features online play. You can play four different games: 8-ball, 9-ball, Straight, and Snooker.

The graphics are pretty realistic, albeit with some cartoony effects – see the little starbursts in the photo above – and the game makes solid use of the touchscreen without making things too gimmicky. For instance, you use the touch interface to aim your shot and add English to the cue ball but you don’t actually have to worry about sliding your finger back and forth to shoot. You simply set the power level and tap the “Shoot” button once you’ve gotten everything in place.

If you’re a fan of online flash-based billiard games, you’ll feel right at home with this one. You can play offline against the computer or a second human player or look for people to play online. In fact, if you’re playing the computer alone you’ll sometimes get a little pop-up message saying that a live person wants to play you online.

All in all, Adrenaline Pool Online is a great way to pass time. As a standalone, offline billiards game, the $5 price tag is worth it. The added online component, though, makes it almost endlessly playable.

Adrenaline Pool Online [Link will open iTunes]