Picnik is part of a new class of Web-based photo editing tools that’s making sprucing up photos easy and fun. Picnik does a lot of the things that desktop photo editors do, but with a lot less work. The basics are all there: cropping, resizing, red-eye reduction. There are numerous effects that can be used to enhance great pictures, rescue bad ones or just to be silly.

Pictures can be pulled in from fickr, Picasa, Facebook, a Web search, URL or uploaded from a computer. It’s easier to select pictures using Picnik than it is on a desktop — unlike Windows, Picnik uses all of the meta data stored with the picture. Type “Venice” and see all of the pictures tagged Venice, instead of having to hunt through the file system.

Here’s a picture from Venice:

What caught my eye that day were the colors of the umbrella. I wanted to highlight them. I added the focal B&W effect. (This really should be called focal color.) I also wanted to convey the sense of gloominess from the high water in the piazza. The vignette effect darkened the edges.

I wanted to highlight the reflection of the umbrella, too, but the focal B&W effect can only be applied once.

Picnik currently offers 19 effects, including sepia, rounded edges, tint, duo-tone. 11 of the 19 are marked “plus,” indicating that Picnik plans to make them part of a premium offering. A cute frog picture next to each effect shows what it does. Each offers an explanation of what it does, plus suggestions of what types of photos to use it on. I’d like to see them illustrate the suggestions with pictures that show off the best uses.

Picnik’s unlimited undo makes it relatively painless to experiment. Right now, this is linear – keep hitting undo to get back to where you were. The undo feature would be enhanced by letting you see the list of changes and undoing ones that you select.

Here’s another picture I wanted to edit:

I cropped it, added some text and doodled on it.

When you’re done editing you can save the picture back to flickr, Facebook, etc. or download it to your PC. The whole process is intuitive and just works.

The hardest part is remembering how to spell Picnik.