Those people you don't know at Discovr have a few Minecraft servers. They're extremely well done but the uptime is a little unpredictable, from what I hear they're having a few problems with Bukkit or something. Anyway, here's two of their best:
Well, it's been a few days, but I'm back with some great news. Minecraft's transition to iPhone and iPad has been CONFIRMED. It'll probably be a little different on iOS, but hey, it's Minecraft.
Though, I wish Notch would pull Java out of the equation here before attempting SSK.