I just read your article about integrating Active Forums and private messages, and had me thinking about doing the same for Simple Gallery.

Simply: From that same profile/bio page in Active Forums, provide a link to "My Gallery"...

The "catch" is the Gallery Folder needs to be associated to the user.  Someone had suggested that Simple Gallery provide the capability to create an album based on their username...  Example:  User goes to gallery, and if that user does not have a gallery set-up already, they could create one based on their username (one button: Create Personal Gallery) that only they have permissions in.  Now when creating the link in active forums, should be able to grab the profiled username to create the link into the proper Simple Gallery folder.

There are many posts in ASP.net forums regarding Yahoo Profile type functionality...  And there is one company that is offering it (but the implementation is not optimal)..

Providing the above Simple Gallery feature, integrated with Active Forums (and the Priv Mess. integration) is one heck of a Profile combination!!!   

I think you'll get a good number of new subscriptions with this configuration if you added the "User creates own album" item.