#2 - Aug. 10, 2010, 5:38 p.m.
At this time, the Battle.net Mobile Authenticator is not supported through Boost Mobile, Thegreatness. Do you by chance have an iPod Touch or an iPad? If so, you would be able to download the Battle.net Mobile Authenticator application from iTunes.
In the meantime I would highly recommend purchasing the authenticator via the online store. You may also wish to check back periodically for any updates the list of mobile providers who offer the Mobile Authenticator app.