Olha só o que achei: http://www.chipx86.com/blog/?p=140
O link acima fala sobre tags no nautilus.
Just a little preview. It’s not done yet, but will be shortly. What you see below is a small python module, a useful command line utility (well, that’s not shown, but if you check the gallery these are in there will be a full-size screenshot showing one), and plugins for Nautilus, GNOME-VFS, and Deskbar. There are plans for Beagle support in the near future, and to make the system more robust.
Stay tuned. There should be a release soon.