[vyrotek]

So is the real service the ability to receive responses? Can't you send SMS messages via email for free already? I guess the ability to send messages without knowing the carrier is pretty useful.

I've used sources like this in the past to send SMS messages: http://www.livejournal.com/tools/textmessage.bml?mode=detail...

[stirman]

The problem Penny SMS solves is, without knowing the carrier, it is very hard to figure out where to route the messages to, since someone may have switched cell carriers, even multiple times, but retained the same cell number.