Jing Project is an interesting new free tool for sharing screenshots and video (screencasts). It is quite similar to Skitch. It provides video recording which (AFAIK) is unavailable in Skitch, but Skitch [seems to] have more options including support for iSight. Both of them let you upload captured content to their sharing portal or any service such as Flickr or a subset of FTP/SFTP/WebDAV server.