I find that many of the games I play would benefit from the equivalent of physical notecards; that is, the ability to have arbitrary text spatially located on the virtual table. Especially in games which aren't miniature based, I need to be able to put some text somewhere on the board and then be able to move those notes about the board as needed.
The built-in text tool doesn't really work because the size of each text box is defined by the amount of text used, and each box, as far as I could tell, can't have a background color.
One option would be to let users 'group' objects, so that a notecard would just be a rectangle and some text grouped so that they move about together.
Alternatively, some sort of blank token that can have text or images added to it would work.