Skitch, arguably the best free screenshot capturing service for the Mac, has relaunched with a new emphasis on sharing images with friends and admirers. In addition to quick screengrabs, resizing, mark-up and upload, the service now includes a lightbox view, subscriptions, comments and is now ad-supported.

Co-founder Cris Pearson says a web uploader and a Windows version will be available soon. His shots are here on Skitch and he recommends following other users including designers Wolfgang Bartelme and Chris Messina.