A conversation consisting entirely of 140 character-or-less "tweets", or Twitter updates, on the micro-blogging website, twitter.com. Twittersations rarely contain legitimate Twitter updates and are instead more of a slower form of instant messaging.
Jack: @Jill How was your Holiday?
Jill: @Jack It was great, we had lots of food and drinks! How was yours?
Jack: @Jill Oh you know, the usual! Lots of family friends came over. Wish you were there!
Jill: @Jack Wish I was there too, it sounds like a lot of fun. Did you hear what happened to Janet at the party?
Janet: @Jack @Jill She got pissed off when she got fifty twitter updates on her phone from a stupid twittersation.