I've been playing with some cool stuff that's in Ubuntu: acl's and kio-slaves

ACLs are Access Control Lists, they can give finer control over access to your files than the normal permissions allow.

KIO-slaves are KDE-specific, but can still be useful to GNOME users at times. In particular there are some extra packages buried in the ubuntu repositories.

Read on for more Ubuntu goodness

*note* the packages mentioned might not be available for hoary, or they might require that the universe/multiverse repositories are enabled. I'm using breezy preview with universe/multiverse