I think my experiences with whiteboard effectiveness are limited to

1. Writing down pseudo code for solutions. 2. Diagrams for architectures. 3. Flow charts for possible actions during problem solving.

But if you ask me to write down a real program in whiteboard, I find myself starting to got interrupted by thoughts about erase lines, moving blocks around and worrying about my writing is too big and board is too small for my code.

I think shared whiteboard is definitely a very good tool for discussions. But for me, even a rudimentary editor like notepad, vi helps me more in handling all rewriting/visualizing/pondering process. Probably I am not those programmers who can write down code without worrying about rewriting them. For me, write a program is like oil painting involving constant changes.