Looking for some suggestions on Menus for Categories

Hello,

I am trying to figure out what to do with the huge category menu in the right hand column of this website: https://www.casualvoyeur.com

The theme I am working with is a modified version of twentyten.

The menu is taking up way too much vertical space, so I was thinking a good place to put it may be below the header somewhere as a drop down menu or as a portion of the header which expands like the city choice menu at the top of https://www.groupon.com/

Wondering if anyone knows of any good plugin to create a Category menu with. Thank you for any suggestions!