Besides the size of GoToobs, they aren't airtight either, so if you leave something in one between trips it tends to dry out. Good idea, but very badly executed.
Bed Bath and Beyond sells small screw-top containers for travel purposes, and I have some of those, also, as someone mentioned, the Container Store is a good source. I find it preferable to have something durable I don't have to worry about replacing, so I got a clear, zippered cosmetic case when the 3-1-1 rule came out, and although it's actually a little smaller than the approved size it works fine for me.
wg