I have a codePlex project I started that has a toolbar object much like Kodigo, PttB and VS. It supports many features of the others and uses the PB dataWindow to do all it's drawing and interface. It uses a minimum of API calls and supports; check/uncheck, resizing, toolTip, enable/disable and has both a mouse and keyboard interface. I am working on the documentation and licensing, but if you'd like to take a look at it, I can package it up and send it to you.
It does not use any PBNI code, nor any external DLLs other than the Windows API.
I plan on building other interface metaphors, like outlook shortcut bar using the same methodology.
Below is my test window:
