This means users using Picasa can click the edit choice from the Edit drop-down menu or from the Picnik icon to add funny comments to their photos in thought clouds, or add stickers and other doodles.
Users can also execute basic edits such as cropping and resizing images, or changing colors. Users can save the edits to their Picasa Web album by replacing the existing image or making a new copy.
Picnik users who paid the $25 per year for the premium package of advanced editing tools and additional effects, fonts and stickers can still do so from their Picasa Web Albums account.
Google's integration of Picnik comes just two weeks after Facebook began testing new tagging technology on Facebook photos.
Facebook gained this technology when it purchased photo tagging startup Divvyshot in April.
Essentially, Web photo capability for consumers is another battleground Google and Facebook find themselves at opposing sides.
While Picnik is geared to let Picasa Web Albums users have fun altering photos, photo tagging is a more sober utility geared to help Facebook users organize and identify people in pictures.