The default install of Tikiwiki uses moreneat theme that has ))::(( to expand and collapse the menus. If you would rather have + and - to expand and contract the menus as in this site,
- Admin -> Sections -> General -> change the theme to tikineat
- while there, tick 'display menus as folders'
- Replace fo.gif (for +) and ofo.gif (for -) in your tiki's /img/icons w/ those on this site (or any other similar images) respectively.
Flash screen recording of the above:
http://sridharkatakam.com/sri-addons/flashots/tikiwiki/PlusMinus
The recording can also be downloaded at http://sridharkatakam.com/sri-addons/flashots/tikiwiki/PlusMinus.rar