Isn't this alredy there? On my board, all the users have to do is create at least one category and their gallery isupand running.
Yes, you are correct, however, the mere fact that they have to "create at least one category" is the issue. Not sure what sector of the population your dealing with but unless PC oriented the majority have an issue with "creating one category and their gallery is up and running" !
If it was that easy there wouldn't be so many people having to make tutorials on how the gallery functions not to mention the endless emails I get with regards to "how do I XXX" in the gallery or "how do I get started in the gallery".
If the gallery automatically created a category and gallery for the user it would remedy 99% of these issues. Even if the category was just "Username's photos" or something similiar.