Sorting the Jewels from the Junk in the iTunes Store

Remember when cell phones were just for making calls? The new iPhone 3G, which launched on July 11, dials phone numbers, but it also runs some 800 add-on applications — developers are creating more daily — that enable you to compare hotel room prices, read Shakespeare, even examine brain scans. About a quarter of the miniature applications, or apps, are free (others mostly cost less than $10 each), so Apple users are snapping them up like candy, with 10 million downloads so far. Glitches may be common as the programs work out their debut-stage kinks, but here are our picks for the coolest of the free programs.