This magnetic clip snaps your tube back in its place, securely, quickly and without much effort at all.
Platypus says:
Magnetically clip your reservoir’s drink tube right where you want it for easy retrieval. Just attach the clip to your pack strap or clothing and hook its magnetic mate to the hose to secure your drink tube. This accessory fits both 1/4” and 5/16“ diameter drink tubes.
Whilst it's possibly a bit gimmicky, Platypus' Magnetic Drink Tube Clip does work quite well and if your moving quickly this takes no effort at all to secure your hydration kit tubing back where you like it.