This mod by Schnoggo creates a small, movable window showing your current money.
Schnoggo's SimpleGold v2.0
Patched for WotLK by Jaruzel:
* Updated for patch 3.02.
* Relocated the tooltip (cursor always obscured total gold where it was).
* Reformatted the money values in the tooltip to something more readable..
Description (by Schnoggo)
SimpleGold is a World of Warcraft AddOn.
Is creates a small, movable window showing your current money.
Mousing over the window displays a tooltip summary of the gold on all your alts.
Shift-clicking on the window will cycle through different background colors/transparencies.
Why would you want this?
You just want to keep an eye on your gold!
Perhaps you want to modify your interface - this provides a nice little money panel.