The new Public Radio App for the iPhone solves a familiar problem for fans of This American Life and A Prairie Home Companion: What do you do when you reach your destination before the program is over?

Forget about sitting in your car to catch the end of the program. The $2.99 app, available now in the iPhone's App Store, lets you pause and rewind public radio streams from NPR, PRI, APM, and local public radio stations. It also has an alarm clock for waking up to public radio and TV Guide-style listings so you can see what shows are coming up.

Combined with on-demand streaming of more than 300 programs, radio bookmarks that can be picked up on your computer, and claims of a new streaming engine to avoid interruptions, and Public Radio App seems like a powerful program for NPR buffs. All that's missing is the occasional pledge drive guilt trip, which you're sure to run into while listening anyway.

But before you rush to the App Store and spend "the price of a grande latte," as the developers put it, consider that there are other free public radio apps available. Public Radio Player 2.0, for instance, has on-demand streaming, which is arguably the most valuable feature in any of these offerings.

Public Radio App's defining feature is its DVR-like features for live streaming (though you'll still need an Internet connection to resume playback later). I haven't tried this app yet, but it seems to cater to the die-hard public radio buff, the one who'd rather listen to whatever's on than cherry-pick individual shows.

For these folks, maybe an occasional pledge drive guilt trip wouldn't be remiss after all.