Photoshop Lightroom 2.0: Merging Lightroom Catalogs (5:43)
-- Posted 11/17/08
This tutorial shows you how to merge different Lightroom catalogs and move files between hard drives so that the work you've done in the Library module is preserved and Lightroom always knows where your images are. This technique is especially useful if you have created a separate catalog while on vacation or on a location shoot and now need to merge it with your main Lightroom catalog.     
Related tutorial: Moving Files in Lightroom