Short answer, no

Long answer, these guys have been promising one for 6
months or so.

http://www.swimman.net/pages/859129/index.htm

They resemble the USB flash players like the Muvo or the new flash players that Rio is supposed to come out with sometime this year. You could use one of these with a waterproof bag and headset if you're looking to be jog or hike with it.

You could get a Sony WMFS420 Cassette Walkman with one of these http://www.romemp3.com if you are planning on submerging it.

This link may be helpful http://www.ainst.com/save/wresistant.html