Picasa

Picasa is an image organizer and image viewer for organizing and editing digital photos, plus an integrated photo-sharing website, originally created by a company named Lifescape) in 2002 and owned by Google since 2004. In July 2004, Google acquired Picasa and began offering it as a free download.

Native applications for Windows XP, Windows Vista, Windows 7 and Mac OS X (Intel only) are available through Google Labs.