Picasa2 is a photo organization program for Windows developed by Picasa, Inc. (formerly Lifescape Solutions). It is similar to Apple's iPhoto for the Mac platform.
Photos can be added either by searching a directory or by importing them from a digital camera or flash memory card. Photos are organized into albums, which are then organized into collections. Photos can be associated with labels that do not mirror the directories the photos are in. There are three views:
Photos can be captioned or given a gold star (similar to Gmail's starred messages) as a rating. Picasa2 includes a powerful inline search capability similar to iTunes: photos are filtered as you type a query. You can search against captions, resolutions, keywords, etc. Results can be filtered by starred photos and/or by date.
Picasa2 includes fairly advanced photo editing capabilities for a free program. Pictures can be cropped, rotated, have red eye reduced, or a large number of other operations such as sepia, black and white, or a one-click "I'm Feeling Lucky" edit to brighten and enhance photos. Edits are non-destructive: They can be undone at any time as the original photos are stored in hidden directories.
Photos can be emailed from the program (using the system email client, Gmail, or an internal mail sender), or they can be passed to Hello, Picasa's sister program, to send to another Hello user or to BloggerBot to be posted on a Blogger journal (or blog, if you must). This is the best method, if possible, because Hello was designed specifically for transferring photos across the Internet. Picasa2 allows archiving photos and burning them to CDs and DVDs. You can also order prints online right from the program.
Problems
As of 2005-01-18, Picasa 2.0 still has a few missing features that were requested during its development:
http://www.picasa.com/