Like to sketch?  How about a free online tool that allows you to sketch with pressure sensitivity?  Steve Mason has created a online sketching program with a simple interface and nice feeling tools make quite an enjoyable experience.  When you are done sketching it saves your art, into the collective creative whole, and allows you to see what others are sketching.  Check it out at http://www.smason.com/flash/sketch/Shell.swf.  The idea if incorporating this type of concept into any web based meeting could allow for all sorts of visual brainstorming.