Unless you can just text directly to facebook.
You can, according to
http://www.facebook.com/mobile/ :
Facebook Mobile Texts- Update your status or send messages to friends using texts from your mobile.
I'll be frank- I don't text. I tried to find a phone plan that doesn't even have the capability.
I don't much either, but I think not having the capability is foolish, for the reason given earlier: text often gets through when voice doesn't. They use a different system, based on store-and-forward, that can exploit brief moments of signal.