I’ve been whining for about two decades that no one in the corporate glass towers built on the plastics industry was capable of recognizing the full potential of the zip-lock plastic bag. In December of 2006 they finally took a small step. The dimensions of the bags increased from inches to feet.
S. C. Johnson & Son, Inc. introduced the “big bag” Ziploc®. They’ve launched a television advertising campaign targeting the United States giant Tupperware® market. Store your sweaters in summer, your old books, anything that might have previously gone in a cardboard box.

As a traveler I immediately thought of a dozen other uses for super-light, easily-sealable, re-useable and cheap enough to dispose of flexible containers: laptop protection, emergency poncho, pack muddy boots or wet swimsuits (don’t forget to take them out as soon as you can or they’ll literally rot in the tropics), segregate dirty clothes from clean, container for your extra stuff when you store it at a hotel while trekking, keep food and beverages from leaking on your pack contents.
I’m not sure they’re tough enough to replace the trash compactor bag for all applications, but it’s tempting. Just get a few and stick them in your pack; you won’t be sorry.
Unfortunately they aren’t perfect yet the flexibility along the top is limited because the zipper remains relatively ridged. If you really cram it you’ll lose the seal, but they’re headed in the right direction.
For extra security you can use the rollover bungee method described on the trash compactor bag page after zipping.