I mentioned these waterproof "saks" several meetings ago and promised to provide some information on there purchase.  They are available from CampMor under the name Aloksak in 3 sizes (6x6, 9x6 & 5x4).  The CampMor item numbers are 75202, 75203 and 75204 (respectively).  According to the description provided by CampMor:

• Patented 100% waterproof, leak proof, liquid tight liners.
• Great for wallets, medications, passports, remote keyless entry devices, documents, small maps, film, batteries, jewelry, cash and other small electronics.
• Most electronics can be used while protected in the Aloksak®
• Certified watertight to 200 feet.
• Soft-sided: Safe, shatterproof, quiet, holds oddly shaped objects
• Simple as using a typical zip-closure type bag, but with the liquid tight protection of a hard case box.
• Durable: 6 millimeter film of the Aloksak® is on par with PVC of the same thickness in terms of durability, but has a lower cold-crack tolerance (-40°F) than that of PVC/Vinyl (0°F).
• Qty: 3 bags.

/r,

d-sqrd