This is one-class util, avaliable http://burnandbass.com/debug/#intro , on the page you can see demos, howto and more 
This util have several purposes - when is created on the stage is added stats bar, showing the current memory in use and the frames per second. The bar always stays on the top of display list, so it is always visible. The other (very useful in my opinion) function creates bubble with text and adds it to the stage, fade it out after a couple of second. If you use it instead of trace() you can get output in browser Drop me line if this helped you
