Not that your duct-taped, yellowing zip lock baggie isn't great or anything, but your phone deserves some better protection. The Blackburn VIP SL Ride Wallet protects your phone or MP3 player from sweat, rain or whatever, but still lets you use the touchscreen like you normally would.
Semi-transparent nylon is lightweight, waterproof and easy to hold with sweaty hands
Touchscreen compatible front means you can use your device without taking it from the bag
Easy to close seal
420D TPU nylon is tough, and makes this ride wallet more durable than your baggie