What's a good budget app for the iPhone?

I’d like to have something that lets me set up monthly budget amounts for lots of different custom categories: groceries, children’s clothes, haircuts, etc., and then deducts each entry and lets me know what the balance available is. Is there anything out there like that? I don’t need lots of fancy financial rigamarole, just a method of virtual “envelope spending.”

Thanks!

Take a look at mint.com. It’s not primarily an iPhone app, so you’d have to invest more time in setting it up than an app that existed solely on the iPhone. But I’ve found it to be really excellent and the iPhone app that goes with it is good too.

On the other hand they were recently acquired by Intuit so it’s possible it will get awful soon.