Hi,
I know,..this is not so much related to webGL,...but: couple of months back I have seen some nice WebGL demos (if I remember, than the demo pack was officially announced via mailing-list) and one was using a nice API for 'menu' that was drawing on top of the canvas. PLEASE does anybody remember?

I have dat.gui but it is a bit limited.

Once again sorry for this 'not 100% WebGL' related question but ,,.... its as close as I could think.