by bars you mean rows?
2 then. quicklaunch on the left, running processes on the right, but both are 2 rows high. Sometimes the buttons for the individual running processes can start shrinking with 2 rows in 2048x1440, I almost never bother to close anything

ObjectBar helps this situation immensely with the XP style grouping.
A lot of people I know move the taskbar to the left or right side of the screen, what does that count as? Or what if you drag the quicklaunch off of the taskbar onto it's own floating window?
For an extra interesting taskbar at work, try this:
1. Right click taskbar
2. Select Toolbars->New toolbar from popup menu.
3. Select My Network Places->Entire Network->Microsoft Windows Network-><your domain here>
4. Hit OK.
Alternatively, C:\ is a good choice for an additional quicklaunch directory.