Just to be clear I am referring to the long stick used in fighting and not all the people employed by an organisation.

Fighting- Enemies are kept away and you protect yourself

Hiking- When walking from place to place staves can be used for support, if injured leaning on a stave can be a make shift crutch

Disguise- Not a distinct weapon unlike a sword and it can be used in a disguise to appear injured or elderly.

Lantern holder- Spread the light further than human reach

Magic- The staves that Gandalf and the wizards in the Lord of the Rings have hold magic, marks could be etched into wood to hold power for times of need.

What else could a staff be used for?