Twit. Er
Signed up for twitter earlier and it looks like fun.
Btw, I wonder if K618 can be made compatible with Mac OS X without the plugin from mobile.feisar.com. The one from mactomster.de doesn't appear to work with iSync 2.4. -update: this is the old plugin for pre 2.4. The new set is no longer free.
If you're wondering why I'm wondering about the above, check out my twitter. I appreciate if anyone can help me set up twittering from my phone. The number they gave me for verification via sms doesn't seem to work.