AT&T is applying a cell phone-like pricing model to netbooks on a trial basis in Atlanta and Philadelphia. Through this offering, you can pick up a netbook for as little as $49.99. Of course, there’s a catch: You’ll need to sign up for one of AT&T’s Internet at Home and On the Go plans in order to get this special pricing offer. AT&T’s netbook offerings currently include the Acer Aspire One, Dell Inspiron Mini 9 or Mini 12, and LG Xenia. AT&T’s Internet at Home and On the Go plans include AT&T’s