OK, so your 100 feet away from your machine and want to change your standard wand to a telescopic wand or start using your surface cleaner or water broom.

Do this:
Drag your hose and walk to your machine, turn off your machine, change to your new tool, turn on your machine and walk back to your work area.
Or this:
Turn off a ball valve, change tools, turn on the ball valve and go to work.

I'm for the ball valve every time.  Simply click a ball valve on the end of your pressure hose and you can save a lot of work.  Ball valves come as a kit, complete with quick connectors, so they are easy to put on and off and can be installed anywhere along the line.

Ball valves are a little heavy, so there is a small price to be paid if you lug one around all day but for those times when changing tools back and forth regularly they are simply the best!