The gambling site satoshi bones uses addresses that start with
1bones, such as
How did they generate such a vanity address?
Bitcoin Stack Exchange is a question and answer site for Bitcoin users, developers, and enthusiasts. It only takes a minute to sign up.Sign up to join this community
there are applications, which take the starting text and generates milions of new addresses until the generated address starts with the selected text. It's pretty fast for short strings (3 characters). you'll wait about few minutes for 5 characters (case insensitive).
one such application is vanitygen.