So have you ever noticed how often the mouthpiece of your hydration bladder tube drags on the ground when you take off your pack or sits on your floormat in the back of your car when you throw you stuff in after a ride? 
What do you use to keep the mouthpiece clean and protected?
I use the rather low tech system or strapping a bit of plastic over the mouthpiece and securing it with a rubber band but I wouldnāt mind some slightly more sophisicated ideas. 
A guy I know uses a trick āfinger gloveā thingie(that performers use).
yeah I donāt think a bit of dirt is gonna hurt, I usually dont worry about it or just try keep the mouth piece off the ground. Crikey that plastic sounds very sophisticated to me!
True enough a little dirt isnāt a big deal but if you saw what was collecting in the back of my carā¦
I just donāt savour the thought of sucking on what the pack may have been kicking around in.
The āfake fingerā is a hilarious and creative ideaā¦LOL
I place the tube and mouth piece inside the compartment where the bladder lives. On my camel back I open up the top velcro, place the mouth piece end of the tube inside and seal it back up.
I just got a new pack with a zippered compartment where the bladder is, and will do the same with that.
The Camelbak Thermal Control Kit may be what you are looking for. Itās a bit pricey though. If you are that worried about it, you could try cutting a finger off a latex exam glove and cover the bite valve with it.
They even sell the cover by itself for $6 on the CamelBak site
Iām lucky Ive got the Camelbak SnoBoundā¦
Insulated, comes with a mouthpeice cover, and a cool zipper to hold the tube close to you, so it doesnāt drag on the gound.
Wow, that is one slick pack Catboyā¦nice!
Thanks for the suggestions about the mouthpiece coverā¦I didnāt know they made them, I think Iāll get one. They should come standard with every hydration pack, in future, I figure.