Picasa3 is the latest software release by google and is a successor to Picasa2.7.Here are the shotcut keys for exploring all new PICASA3 web album.
Shortcut for selecting PHOTOS
[ctrl]+[A]: Select all photos in album
[ctrl]+[D]: Deselect photos
[ctrl]+[I]: Invert photo selection
[Home]: Select the first photo in ur album
[End]: Select the last photo in ur album
Photo Tray
[ctrl]+[enter]: Locate the photo file on your computer
[ctrl]+[o]: Open a file on ur computer
Shortcut for viewing PHOTOS
[ctrl]+[1]:View ur photos as small thumbnails
[ctrl]+[2]:View ur photo as large thumbnails
[F11]:Use picasa in full screen mode
[ctrl]+[4]:Start a slide show
[ctrl+[5]:View ur time line
Shortcut for editing PHOTOS
[ctrl]+[3]:Open an image in edit mode
[ctrl]+[R]:Rotate the image clockwise
[ctrl]+[shift]+[R]:Rotate the image counter clockwise
[ctrl]+[shift]+[H]:Flip image horizontally
[ctrl]+[shift]+[V]:Flip image vertically
[ctrl]+[shift]+[B]:Add black and white effect
Miscellaneous shortcut
[ctrl]+[E]:Email selected photos
[ctrl]+[P]:Print selected photos
[ctrl]+[shift]+[P]:Print album contact sheet
[ctrl]+[F]:Search
[ctrl]+[K]:Add keywords to ur photos
[ctrl]+[N]:Create a new album
[F1]:View help content
[X]:Exclude a photo in import mode
Shortcut for watching VIDEOS
[/]:Pause/play videos
[,]:Rewind videos
[.]:Fast forward videos
