Find the 3G band for Nexus One

Given a nexus one (rather any An开发者_StackOverflowdroid phone), is it a way to find out which 3g band it supports (t-mobile or att), without inserting any SIM cards ? currently I'm just interested in nexus one, but generic info can be useful too.

Yes there is. Take off the back cover off the Nexus One, remove the battery and read the FCC ID number at the top of the black area.

The FCC # for the AT&T version is NM8PB99110

The FCC # for the T-Mobile version is NM8PB99100