[X4U] Drop down menu of active programs

[James Hurley]

My multi-button mouse slipped off my desk the other day and in my 
efforts to retrieve I caused a drop down menu  appeared in the upper 
right hand corner of my  screen which appeared to list all active 
programs--it just as quickly vanished so I didn't get a good look at 
it.

I couldn't find the keyboard or mouse buttons configuration to 
duplicate this apparition. Anyone know what it might be? It looks 
useful.

(OS 10.4.8)

Jim