Picassa...Already posted by Jessie
A bit about picassa from google...
There is a download (see below -- there's a link) that will allow you to edit your photos on your computer (sort of an easy photoshop that's free, that you can post to your blog directly from, and it includes a "collage" option). This download, although it's connected to blogger and picassa web albums, is separate from the web album service that google offers.
Picassa- the download can be used with or without the web album; likewise, the web album can be used with or without Picassa (only the download will enable editing of photos and the post directly to album/blog features, but the web album offers free photo storage space and does not require a download to use the service)
Here's a random example using something I already had online (edited with picassa's software download, and also shown on the picassa site)
Logan the Ducky Diva
Click above and you'll see the webalbum for the photo (google calls it the "cover photo") shown. About the collage, Using the software I downloaded (Picassa--that lets you edit and make bloggable -- collages and other fun things), I created this collage:
From Logan the Duc...
Here too, it's hosted by web albums. To see the full size image (a collage is saved as a new, single image file) you click, just like for the album, and be taken directly to the collage (where it's located inside the same album as the first example) online. To see how to make a collage, click the collage and read its caption, b/c that's where I put the basics for creating one (really, it took me about 20 seconds to create- it took longer to write the caption than to make a collage out of the photos!).