Yes, that would be a nice feature, it has been mentioned a few times. Have faith, it will get added in. There are new features almost every day...

I'm not sure what you mean by "one-time," as the chatterbox message remains until you clear it. Also, when people spot errors in your posts, they will often send a chatterbox /msg about it, so that you can fix it, so it might not be a good idea to have it off. Or, you could just grab the XML for your private messages...

Paris Sinclair    |    4a75737420416e6f74686572
pariss@efn.org    |    205065726c204861636b6572
I wear my Geek Code on my finger.