Inko is a peer-to-peer collaborative whiteboard for iPad, iPhone, and AppleTV that lets you draw together & brainstorm even without internet connection.
A simple real-time whiteboard built for teams - collaborate the way you like, use your browser, tablet or smartphone, in the office or on the go.
Brainstorm and discuss your big ideas, upload designs and easily share feedback collaboratively. Get started quickly with using hand-crafter templates and shapes. Draw your teams together.
Cr4yon attempts to provide the same feel as real life whiteboard via a collaborative simple drawing interface.
You can draw and add text (HTML canvas) easily.
The product is at an early stage obviously but is very encouraging.