So, what do you do when legions of iPhone users continue to suck down massive quantities of mobile data? If you’re AT&T, you promise an even faster route to do so. This week, America’s exclusive iPhone carrier has just announced that it will be upgrading its 3G network and readying it to deliver “considerably faster mobile broadband speeds.” Starting later this year and continuing into 2011, the network upgrades — which will integrate High Speed Packet Access (HSPA) 7.2 technology — will enable it to deliver