3oz glass pico tank?!

some new fangled Crate & Barrel web sight has these;

3.5" square $7

It's probably impractical as a viable fish tank
but you could use it for other fishy things like;

- isolate a plant or fish for macro photography
- display or present a plant or fish at your next swap meet in a clearly viewable way
- upside down can isolate a delicate plant while it's first taking root
- partially buried and covered side way down might pass as a observable cave
- hold and display any of your live food, before their ultimate demise
- use it in a larger tank with gravel and a rooted plant established in it,
in order to raise that feature plant above the gravel line in a classy way.
nice idea for growing Rotala Goias since the stems will creep over and down.
- mini aquascape gift container you would first establish in a larger tank,
then you would remove the cube, gravel plants and all, and give it as a gift,
that the recipient would ultimately integrate into their own planted tank.
it would probably be better if you used a fibrous substrate that the plants
could adhere to, so they won't get shifted around during gentle transport.

I'm sure the collective genius assembled here
can come up with a few more fish applications.