If you need those features, you're welcome to have a look at my phd project, http://sdcl.ics.uci.edu/research/calico/, check out the second video. Admittedly, it's a java application rather than a webpage, but a few companies have found it useful so far. The project is available on github here: https://github.com/uci-sdcl/calico.

A similar site I built (http://stoodle.org) supports these three features in addition to group voice conferencing through Twilio.

I just tried stoodle, but I'm not seeing the data being replicated across windows. e.g I have some doodles here in http://stoodle.ck12.org/class/53f619cc417e3 but when i open this link in another chrome tab (or a different browser ffox), I am not seeing anything

Haha, that's awesome :-) thanks for sharing.

Text is also a feature I'd like to see. Sometimes its easier to just type something than gesture each letter

I fully agree, especially for the text (it is hard to write with a mouse!).

In addition, basic shapes like line/rectangle/circle would be welcomed (I am terrible at drawing a circle with a mouse).

I got the exact same feeling after using it for 2 seconds. Then watched his video demo and understood why he did it that way.

He did the product with tablet users in mind.

You can probably use a wacom tablet instead of a mouse. It makes it a lot easier to draw freehand.

Yes typeable text is high on the to-do list (although on a touch-screen tablet it's probably just a efficient to draw the text)

It might be just as efficient in terms of the amount of time taken to draw/type it, but typing it lets people copy/paste and ensures legibility.

I agree, these 3 features would push this over the top in terms of usability. This would make remote consulting so much easier too.

Edit: Well done though, awesome 1st cut :)

Re: #2, feature exists. See Options > Insert Pic.

Outstanding! But I would not think to look under "Options" for an active feature like this.