I never thought to use these until my most recent backpacking trip. I bought a great backpack, only to realize it was bit too small to fit all that I needed to bring for two weeks. Like a sign from the travel gods, I stumbled upon Space Bags 3 days before my trip.
Duh. Why didn't I think of this before? They were perfect. In case you don't understand how they work:
1. Put in clothes 2. Seal Bag 3. Roll bag to push air out 4. Pack.