Water Resistant Pouch for Cycling / Running.

[Naolin]

I like to take my phone cycling and usually put it in the pockets behind my cycling Jersey. On long rides if I sweat through my Jersey or even just if I get caught in bad weather I would like to have something to put my phone in to protect it from a little water or humidity. I know some guys just put it in ziplock bags and that there are some water proof bags on amazon but the only one's I saw on amazon are huge and bulky since they try to be 100% water proof.

I'm just looking for something like a slim pouch as an extra layer between the phone and the Jersey, preferably water resistant.

Any suggestions, ideas?