Less than 15 months ago, AT&T was the only U.S. carrier that sold the iPhone. Now, that number has risen to nine. Effective today, five new regional carriers have joined the iPhone cavalcade, according to CNET. And no, none of these go by the name T-Mobile.

Alaska Communications, Appalachian Wireless, Cellcom, GCI, and nTelos are now selling the iPhone 4S, each for $50 less than the price tag offered by the three largest nationwide carriers, AT&T, Verizon Wireless, and Sprint. Each is also offering the iPhone 4 at either the usual $99 or for $50.

Cellcom

C Spire became the first regional iPhone carrier in November. Sprint (in October) and Verizon (in February 2011) became iPhone carriers last year.

Alaska Communications obviously covers Alaska, as does GCI. Appalachian Wireless covers parts of Kentucky and Virginia, while Cellcom covers Wisconsin and Michigan. And nTelos covers Virginia and West Virginia, and parts of Maryland.

Of course, T-Mobile, the nation’s fourth largest national carrier is still iPhone-free, despite trying to get Apple’s handset since last fall.

Since then, the U.S. Department of Justice scuttled AT&T’s quest to acquire the Deutsche Telekom AG subsidiary. In addition, T-Mobile recently introduced a new ad campaign featuring a leather clad Carly Foulkes on a 1000 cc Ducati superbike.

The campaign is to promote T-Mobile’s 4G network and is a metaphor for T-Mobile’s stance in challenging the status quo and taking bold steps, said Peter DeLuca, brand, advertising and communications senior VP., speaking to Twice.

Whether this is enough for Apple to take a second look at T-Mobile remains to be seen.

In the meantime, the iPhone 4S/4 is now available at Alaska Communications, Appalachian Wireless, AT&T, Cellcom, C Spire, GCI, nTelos, Sprint, and Verizon Wireless.