I just told my mom last night (who just got a phone with a keyboard, and thus has no more excuses for poor texting grammar) that to me, proper spelling/capitalization is the same as manners - it shows you have respect for the other person. She replies with "You can't figure out where the capitals go??" D'oh!
She also tells me that text speak is the "wave of the future" and is now socially acceptable. I don't buy it.