Picasa allows you to work with multiple files at the same time. For example you can perform some manipulations (rotate, resize ...add effects etc) on a batch of photos, in a few clicks.
First select your photos ..(Note that: You can add them in a new album, work upon your pictures, while keeping the original files untouched)
- Do a CTRL + Left CLick for multiple selection,
- Go to Pictures tab, scroll to Batch Edit and make your changes.
Here's a list of things you can do:
- Auto Contrast
- Auto Color
- Add Effects: Sepia, Film grain ......
- And many more