SMS (or Short Message Service, not the System Management Server, sorry) is very popular. I heard that some youngster are able to type SMS in the pocket of their trousers while talking to somebody else on another topic (must be females because of reasons we all know regarding Multi-Processing).
If you want to send SMS from a computer one might come to the conclusion that a mobile phone and a computer should be enough. The MSR guys from India did really just that.
It is an SMS server which only needs to have a Windows machine and a SmartPhone and of we go. The thing is based on .net and is a CodePlex hosted project. See more here http://research.microsoft.com/research/downloads/Details/2bdeb3c6-9945-4804-a9bc-0d53704d35da/Details.aspx
The background of the project is interesting and more than game play:
"In our own ‘Warana Unwired’ project, Microsoft Research India (MSR India) worked with a 70,000 person sugarcane cooperative to enable their farmers to buy fertilizer, check their payment history, register their land, etc. via SMS and with significant costs savings versus their existing PC kiosk based system."