Hi financecatalyst,

I bought a GSM Starterkit S3 from www.roundsolutions.com a few weeks ago.

Depending on what you intend to learn and do, you might be afraid about the price (€338.-) but I can tell, you get an excellent starter kit with absolutely all one needs to have a good start.

You can also buy a GSM module only, but the protoboard you get in the kit is really handy (just "plug & play").

There are other GSM modules sellers for sure, so have a look around ;-)