As the album owner, you decide exactly who has access to your album. In addition to the different levels of album visibility, you can also manage the people on your online album access list - the 'Shared with' list. Adding people to the 'Shared with' has the following benefits:
- Easy access. The people on this list are the only ones that can see albums set to 'Sign-in required to view'. Plus, everyone on this list will be able to come back and find the album on your public gallery - http://picasaweb.google.com/[username] - regardless of changes you make to album visibility.
- Email notification. Everyone you invite using the Share button is added to the list and will receive an email invitation to view your photos. Everyone on the list also gets notified when new photos are uploaded to the album in the future.
- Collaboration. You can choose to let people on the 'Shared with' list add photos to your album.
Granting album access
Use the Share button in Picasa or Picasa Web Albums to add people to the 'Shared with' list and to send an instant email invitation to view the album. Follow these steps:
- Click the Share button in the Picasa software or Picasa Web Albums.
- You can add both individual users and entire Google contact groups to the 'Shared with' list.
Share with individual people
In either Picasa or Picasa Web Albums, add the email addresses of the people you'd like to share with in the 'To:' field of the sharing dialog.
Share with Google contact groups
In Picasa Web Albums, you can also share directly with your Google Account contact groups - Friends, Family, Coworkers, etc - rather than with every individual person. In the Picasa Web Albums sharing dialog, just check the box next to the contact group to give access to all members of that group.
- Click Send to complete the share.
You can also add Google contact groups to your album's 'Shared with' list when creating a new album or when editing an existing album in Picasa Web Albums. When sharing in this way, members of the group will not be sent an instant email invitation, however they will be notified of your activity if they are opted into the Picasa Web Albums email digest.
Removing album access
You can remove an individual or a Google contact group from the 'Shared with' list at any time. In the 'Shared with' list, click the 'x' icon 
next to the email address or contact group to remove album access.