I like the glass jar concept. Tearing a tank down is so labor intensive, not to mention stressful for the other inhabitants.
I've had success in the past with a home-made "fishtrap". I used a plastic 1/2 litre bottle with a wide mouth opening. Using a series of rubber-bands and pivot points I was able to bait the trap and a "little door" would close the opening. Now that I think about it, I had way too much time on my hands when I made that one. I caught something every night. Everything but the "stupid" lobster that the trap was intended for...
Drop by if ya' wanna' borrow it...