Google's Picassa 1.0 v. 2.0?

It's a no-brainer (it's free!), but if you haven't upgraded to Picassa 2, the upgrade is seamless, and here are the new features that really stand out for me after a few months of use:

- Well-integrated image processing tools (black and white effect, redeye reduction, etc.)
- New creative tool that lets you build composite photos (place photos in a 3x3 grid, etc.)
- Tighter integration with other services (upload to Shutterfly, open Adobe Photo Elements)

Still the best way to keep track of the photos on your computer -- easy and inobtrusive.