Smart Folders offer a lot of possibilities. Here's how I'm using them to track my current projects.
I have created a Smart Folder and labeled it Current Task Items -- it pulls in all files (or folders) that I am currently working on. For instance, I have a contract in Microsoft Word that needs review, a PSD image of a postcard that I am designing for a client, and an index.html page that I need to update on my personal webpage. The problem is that I have those files scattered all over my computer.
I have set the color label "red" as my "current taks items" and then I make sure to label all my current task items in red. Finally, I created a Smart Folder to search for any items with the color label of red. Voila, I have everything within a click.
When I'm done with the current item, I open my Smart Folder, de-color that item, and it's gone. Have fun smarting away!
[robg adds: This is a simple example of how Smart Folders can be used. I don't intend to run a whole series of "here's my favorite smart folder" hints, but I thought this one might give some less-experienced users some ideas. If you have a favorite use for Smart Folders, add your usage in the comments...]

