I'm not sure this is the right place for this, but... I'd like to suggest a change to the beamer docs.
In section 12.5, it recommends to use package fancybox, noting that it provides shadow boxes, double boxes, and oval boxes.
However, the oval boxes are merely rounded rectangles, rather than ellipses, and further, they are not very high quality, in that they tend to be rendered in a way that things look off by one pixel, which is distracting.
It may be worth mentioning that there are other options, (
http://ctan.org/topic/boxing), and perhaps even to specifically mention one or two of them. (For instance, longfbox has real ellipses instead of rounded rects!)