Google's Picasa is a program made to help you categorize your digital photos, available for Windows or Mac. (Mac users often use iPhoto, a similar Apple program with the same basic goals.) Here are the best things about Picasa:
In class today, you'll need some digital photos, so click here to download a small subset of my photos.
Unlike manipulating photos in Windows (or on a Mac, the Finder), Picasa is not designed only around folders, but also includes "Albums".
If you double-click a photo, Picasa brings up a simple but limited image editor, allowing you to adjust brightness and contrast, remove red-eye, and apply artistic filters with large, friendly buttons. It won't overwrite the file on disk until you hit "File -> Save", and even then it will just hide the original in the ".picasaoriginals" folder.
Caution: Picasa is very eager to get your photos onto the internet. For example, with one click you can upload photos to Web Albums on Google+ (this is basically Google's equivalent to Facebook). If you enable automatic cloud backup during installation, Picasa will copy your photos into your Google account in the background--this is a good way to back up your photos, but increases the chances they'll end up on the internet, either accidentally or maliciously.
Also creepy, Picasa is very eager to apply its face recognition to your photos, and can match these to your Google+ contacts. Like Facebook's "tag person in photo", some people might prefer not to have their faces tagged under their real name in a machine-readable database (for example, if your name is Sarah Connor, and you're concerned about being attacked by a relentless robot from the future). Picasa can use this technology to automatically sort people into their own album under "People", but I find the automated detection is pretty unreliable, and it's rather clunky to manually add faces: click people, manually draw a box around the face, and then enter the person's name. Unlike with albums, you can't just drag a photo into the "People" area.
Digital Photos on Computers is an Osher Lifelong Learning Institute course taught by Dr. Orion Lawlor.