The Tango Desktop Project (thanks, William) is an effort to basically de-uglify the open-source scene with a set of completely free (as in beer) icons. This is great news for everyone involved in UI design and a great resource.

Tango defines a standard icon style guidelines document that applications and desktop enviroments can adhere to. Work has started on creating a new base icon theme based on a standard icon naming specification. In addition, we provide transition utilities to create icon themes for existing GNOME and KDE desktops.

Of course, creating your own icon set will earn you more brownie points but if this means that the open-source community can deliver more cohesive interfaces I'm all for it. I see some benefit in utilising such movements as Tango to homogenise (to a certain degree) internet applications. One could thank Basecamp's look-and-feel for many of today's online app stylings and while I don't particularily condone "everything looking the same" (that would put me out of a job) I do see a benefit in getting some sorts of guidelines in place for icons, buttons, forms from their naming to the way they look. Familiarity is at the center of every great UI design and if you can't build an icon, at least use something people will recognise. Things should always work the way people expect them to.