Prepare to be spammed globally. Twttr just launched, a mobile social software app for SMSing your social network developed by Odeo. It's slightly simpler than Dodgeball, not location centric and a bit more viral. Biz Stone calls it present-tense blogging. Ev notes you might want to upgrade your SMS plan and they are working on compatibility outside the US. To me its reply-to-all baked in your phone.
If they support MMS and let me send a photo to twttr and CC flickr, it will be a killer app. But for now, put my SMS' in a sidebar widget or give me feeds I can splice.
Yes, I am a twtt.