Well, my eventual solution to making a context menu would probably end up being a group of objects containing a Text, Box or Panel (for border and background), Sprite (for selection cursor), and perhaps a Dropshadow or another sprite (for optional shadow) object. This would be a bit complex, but have a large amount of flexibility.
But, I was intrigued with the ListBox idea. Actually, the ListBox makes a pretty decent context menu. I made one in nine events. Could be less, depending upon your needs. While it is bit less fleshed-out than I liked, it's rather simple to implement.
I included comments in the .cap
http://dl.dropbox.com/u/5868916/ContextMenu.cap
If nothing else, it's an interesting exercise I may end up making the more complex one at some point. I like those menus, too.