Have you seen the new features at Pic Monkey? I must say, its new collage features are AH - MAZING! They offer super flexible layouts that literally let you build you're own collage dimensions and arrangements. Crazy flexible! It is far superior to the old Picnik and basically rivals what I can do in Photoshop Elements (PE).
Here is an example of a collage I whipped up in less than five minutes on PicMonkey. Pretty good for a free photo editor and only five minutes of my time! With a few more minutes of attention, I could have evened out the face sizes and zoomed/cropped the center image. (This collage was just a test run.)
I made a nearly identical looking collage for family earlier this month with Photoshop Elements, except I made the improvements listed above (evened out the zoom ratio on the head shots and cropped in the center image). Yes, the version I made in PE is slightly better, but it took so much, MUCH longer to create.
I'd show you my photoshop version for comparison, but I don't feel like blurring out her full name (which is included on the "real" one I made for family) so you'll just have to take my word that the new PicMonkey collage features are nearly identical to what I can do in PE.
Go check it out at picmonkey.com!