Full list of (currently undocumented) keyboard shortcuts:

  Note: On Mac, substitute any ctrl with cmd
  
  general:
    ctrl+z:             undo
    ctrl+shift+z:       redo
    ctrl+s:             save (open publish dialog)
    ctrl+i or i:        open info window
    alt+r:              open reply dialog (on a published markup)
  
  tools:
    v or s:             select tool
    a:                  arrow
    m:                  marker
    t:                  text
    l:                  line
    c or e:             circle (ellipse)
    r:                  rectangle
    esc or ctrl+enter:  finish editing a textbox
  
  editing:
    backspace or delete: delete selected shape(s)
    ctrl+a:             select all
    arrow keys:         nudge selected shape(s)
    shift+arrows:       nudge selected by 10 pixels

You can get something pretty sticky-note-ish by dragging a box with the text tool. And yep, we've got some of those on our list.

Aha. Had no idea there was a text tool -- since it's not in the frontpage demo.

Pretty nice, and it's similar. But, no text tools, and no Safari/Chrome support. Also, MarkUp captures the DOM exactly as it is (including stuff loaded in through AJAX), and kills any javascript.

1) Yep. Keyboard only for now (though we're looking into adding UI controls): You can select any shape, then hit backspace/delete. You can also select every shape with ctrl+a/cmd+a. Also ctrl+z/cmd+z and ctrl+shift+z/cmd+shift+z to go back and forth in the history.

2) We've got some ideas about making collaborating easier (revision history, realtime multi-user drawing, wave-style replaying, &c.) What would work well for you?

Thanks for the followup.

re. #2, i think even a revision history, keeping the same URL or a list of revisions on the dropdown should be very useful while you develop the entire product.