Nice example of a HUD development in Second Life though it may be of specialised use.
The tornado Summoning HUD enables the wearer to summon a 40 meter tall, sculpted tornado, complete with particle effects, sound effects, debris, remote control, random movement, and physical avatar suction!
* Summon a 40 meter tall, animated sculpted prim tornado (anywhere you have build rights)
* Tornado summoning animation and effects
* Storm cloud, dust cloud and water spray effects
* 21 types of debris with impact sounds (phantom, temp)