SMS chat for MSN

[epsilon1983]

So I haven't found a thread about this, but I was wondering if anyone knew of any chat apps that worked by using SMS instead of the internet (like older phones do). The reason is that I'm not always in areas where I can connect to 3G or Wifi, but I'd still like to be able to chat through MSN using texts like I used to on my old phones. If anyone knows of anything, please let me know, thanks!