It's publicly available on the App Store now. I just installed it, and it seems to work pretty well. I was unable to automagically checkin at a few places (it seems to rely on the GPS, unlike the Website which relies on Loki), but it's alot faster than the i.brightkite.com webapp.
Also, I just noticed I have 10 invites now. If anyone wants in, drop me a line.
Also, I just noticed I have 10 invites now. If anyone wants in, drop me a line.