Scriblink is an online white board for remote collaboration. I was impressed by scriblink because it requires no add-on software such as flash, runs quickly on my older PC, and allows you a full range of painting and typing options. Very handy when whipping something up across the internet.
My only complaint is that the "save" function (which is supposed to email you a permanent link to your whiteboard) does not seem to work yet. Scriblink also offers VOIP and phone conference options, which I did not test.