Twitter is set to launch its own photo sharing service called twimg.com. The new service will compete with Twitpic, Yfrog, Instagram and Flickr. The announcement is expected to be given Wednesday at the D9 conference at Rancho Palos Verdes, California. This is according to the Guardian. It will be interesting service since most people are already using Twitpic and Yfrog. Will it catch on?