You can't delete your Google Account for Picasa Web Albums without deleting your entire Google Account, and therefore losing access to your other Google products like Gmail or Calendar. However, you can remove all of the content in your Google Account for Picasa Web Albums by deleting all of your albums:
- Sign in to Picasa Web Albums at http://picasaweb.google.com using your Google Account username and password.
- Select the album you'd like to delete.
- From the Actions menu above your photos, select Delete album.
- Click OK to confirm that you want to delete the album.
- Repeat these steps for each album in your account that you wish to delete.