A simple and clean look with big handles to make it easier grab the window edge (e.g. for laptops with awkward pointing devices). The colour scheme is a boring grey, but it's guaranteed not to clash too violently with your widget sets current theme.

The arrow buttons assume a horizontal arrangement of workspaces and change between them in a linear fashion. Pressing the left mouse button moves the window between workspaces. The right mouse button changes workspace leaving the window behind.

Oh yeah, there's no minimise button. Tough.