I am looking for an alternative to iPhoto for viewing and organizing photos. I need something that allows for tags like iPhoto does and preferably something with a full-screen mode for editing. My main problem with iPhoto is that it gets bogged down when you have imported thousands of photos. And I hate having to import photos on external drives before I can view them. I've seen a lot of recommendations for Picasa, but I can't use that 'cause I'm on a PPC.