We’re having some discussion on using radius for rounded corners with regards to achieving it for a table row for the ical events plugin.   At time of writing the radious options do not play nice with table elements, especially if collapsed.

http://www.google.com.au/search?q=css+border+radius+on+table+elements

Thinking about styling the ul /li elements within the table cells and so somehow  achieving the same result.   There are some things to think about though if you want to use it for menus – ie with hyperlinks

http://www.onderhond.com/blog/work/trouble-with-rounded-corners