In Picasa image organizer and image viewer, you can combine photos from multiple folders into a single album in Picasa. Photos that you include in an album remain in their original folder locations on your computer, even if you reorganize or delete photos from the album.
To create an album, you can follow these instructions:
- Select the photos you wish to include in the album and put them in the Photo Tray in the lower-left corner of the window.
- Once all your selections are in the Photo Tray, click the Add Selected Items to an Albumbutton on the Photo Tray.
- Select New album. You can also choose to add the photos to an existing album in the menu.
- In the ‘Album Properties’ window, name the album. Learn more about editing album properties.
- Click the OK button. [source]