Picasa 3.9 includes Google+ sharing and tagging, 24 new photo editing effects, side by side editing and lots more.
* Added ability to upload to Google+: share with circles, post pictures to your stream, and upload images at original size.
* Social Tagging: name tag people in your Google+ circles and notify them via G+.
* 24 new photo editing effects.
* Side by side editing: compare two pictures side-by-side, or compare different edits on the same picture.
* Updated RAW support for pictures from newer cameras.
* Support for WebP files.
* On the Tools > Experimental menu, we've added support for migrating your database to another local drive.
* Improvements to Face Movie maker: number of photos included, chronological ordering.
* Sync now uploads unshared albums privately.
* Improved restoring of virtual albums when you uninstall and reinstall, or move to a new computer. Album data is written to the picasa.ini file now, along with all of your other edits.
* OAuth support: use 2-factor accounts without getting an application-specific password.