Tired of high SMS charges? Use these SMS gateways, which translate emails & IMs into SMS text messages … for free (well, to the sender, anyway – the recipient still has to pay). And when recipients reply, those replies come back to the sender in the same format; in other words, you email someone, they receive a text, they reply, & you get it back as an email.
One more caveat: you obviously have to know which carrier people are using in order to send them a text message, so ask.
The information here came from “The Great Text Rip-Off”, originally printed in the June 2009 issue of Popular Mechanics.