For the ultimate in portability of even your largest project, check out the "GoKnit Green Tote" from KnowKnits. And its design is oh-so clever: when folded up in its own mini-case, you can attach it to your belt or purse strap. Then when you find that great item you've been craving or you want to carry your groceries all in one large bag (it'll hold up to 10 pounds of goodies!), just unfold the tote to its full size, and the mini-case because a convenient inside pocket. Also made of the same machine washable & dryable ripstop fabric as the GoKnit Pouch.
Measurements: Stored: 5"h by 4"w Full Size: 20" by 20"