Good way to keep sawdust out of mp3 player/phone?

I don't yet have a good dust collection system set up so I am currently covering everything in the garage with a fine layer of sawdust every weekend and then sweeping it out.

My problem is that I'd like to listen to music from my phone without getting it covered in sawdust. Even in a zipped up pocket it still manages to get a little dust on it.

I am planning on finally organizing my garage this spring and will be making a storage cabinet that will have room for a tv and stereo speakers at the top. Would love to be able to plug my phone into the speakers without getting it all dusty.

Screened shelf? Put phone in locking tupperware with just a hole for the aux cable? Anyone have any recommendations or a set up that works for them?