I threw in with MobileMe because it seemed like a better deal at $60 than a Flickr Pro account, since I get all kinds of stuff plus photos. Apple continues paying dividends with its very nice MobileMe gallery app.
It's akin to Apple's other MobileMe app, for iDisk, in that it lets you look at the stuff—in this case, photos—you've got stored on MobileMe, and easily share it, as well as check out what your friends have got up there too.
It's fast, and with local caching, you can view photos even when you're not online, and they feel native, too, with full pinch zooming and landscape orientation. The front page is pretty slick, with a ticker of recently updated photos scrolling on top of your list of galleries. It's free, so it's a no brainer get if you're paying Apple $60, $70 or $100 a year for MobileMe, especially since it fills a big hole vs. Flickr on the iPhone. You'll at least feel like you're getting more for your money.
Oh, and I wound up getting a Flickr Pro account anyway. Dammit. [iTunes]