I'm currently working on advertising material, where I have to put photos together, design, etc. in Photoshop.
The resized photos I give into a folder in Bridge. I don't want these guys hang around my library.
Also the exported images, for internet use, etc. I will in futur store within Bridge.
So I have the photos in my library, all derivatives like promotional material, resized photos, or plain foolin' around, in folders within Bridge.