Yep, I know that Picasa has a right click context menu option to edit in Photoshop and many other programs. However, you can’t control how that list in populated.  Photoshop could be missing from the list, or buried down low. This is a one-click solution.  And for those of us who do it often, all the clicks add up.

I’ve seen many of these around the net, specific to version CS3 or CS5, but this guy was nice enough to make a universal button that works for all version of Photoshop.  He saved me an hour and a half of trying to learn Google button API and tinkering.  Enjoy!

http://www.185vfx.com/2010/12/mac-picasa-to-photoshop-button/