After briefly appearing in Japan's App Store, Google's Latitude app is now in your App Store—and this time, it doesn't look like an accident. Stalk friends! Be stalked! It's free! [iTunes via RedmondPie]
Bleh. This really only updates when you open the program or have it in the foreground, from what I'm reading. Probably to spare the battery.
If you want something like this, only better, I'd recommend using Glympse. It's basically the same thing, except you don't need an account, you pick who gets to see you, and you set an expiration time, so it shows you when you want to be shown, and only to the people who you want to see you. Your position opens in a browser window for others, and updates realtime on a computer, and live with every refresh on a smartphone. I've been using for a while, and it's awesome.