As you probably know, Ubuntu 10.10 Maverick Meerkat will be getting "windicators" or window indicators. The initial mockups were only sketches but here are some new mockups designed by Dani Planas Armangue:
And for Ubuntu Netbook Edition:
Note: these are not official mockups, but they are still pretty close to what window indicators want to be. You can read Mark Shuttleworth's comments on these windicators mockups, HERE.
[Image credits: Dani Planas Armangue]