Here's an interesting Vista tip from my colleague, Josh.
Have Vista and Office 2007? Would you like the Office apps to use the Vista Black colour scheme rather than the default blue? Don't bother looking in Outlook - I couldn't find anything here. Fire up powerpoint; click the windows button (top right); click on "powerpoint properties". On the first screen, there will be a drop down for powerpoint color schems: select "black" and click save. This will side-effect all other office apps! (Isn't aliasing a wonderful thing?!).
Anyone else have another way to do this?