Blogger Vinayaka CA details how he uses Google’s excellent photo management application Picasa to manage multiple photo libraries. His solution: Create a Picasa library under another user account (e.g., PicasaUser) on your Windows PC, then put a shortcut to Picasa on your main desktop. Whenever you want to use your alternate Picasa library, right-click the shortcut and select Run as ->PicasaUser. You’ll have to provide the other username and password every time you do it, and this isn’t as clean as if Picasa actually supported multiple libraries (like iPhoto and iTunes do), but it’s a good workaround if you want to separate your pics into multiple libraries. I gave it a try and it seemed to work, but if you’ve got a better method, let’s hear it in the comments.