Empty tank, too many possiblities

[Blinky]

I've been wondering what to do with my empty 20g tank, and I often see people post asking for ideas for their tanks so I thought I'd do the same.
The tank is a 20g tall, with cork side and back walls. The current light is one 15W flourescent so unless I buy a new fixture, plants are out (and my 45g is planted, I'd like to try something else with this one).
I was actually thinking of somehow building a 'cave' wall to go over the cork (which is permanently attached to the glass) and make a blind cave fish biotope, but I'm not sure it would work. I've also considered making a paludarium, but this would involve new lighting and I'd rather work with what I've got.
I'm not partial to any particular fish or decorating style, as long as it's natural (no flourescent gravel or little castles!)
Anyone have an idea they'd like to share? What would you put in the tank if it were yours?

 

[Leopardess]

Its dimensions are just like two 10g tanks on top of one another, right?

Ive been thinking it'd be neat to do a tank that used a lot of round rocks and some moss/grass.

Maybe something like these?

or

Maybe you could do some killifish or badis badis? Blind cave tetras would be neat, esp. with rocks and dark substrate, but Im not sure if a 20g is big enough (don't know much about them). I've seen some large-ish ones at the store before.

Hehe, if you like them and would be up to feeding them, if you were to go with a lot of rocks/hiding places, a bunch of dwarf frogs would be awesome

 

[Blinky]

Great ideas, I love the second picture especially. Looks like a gorgeous book!
The tank's dimensions are: l24" x w12" x h16" - my 10g is l20 x w10 x h12 so the 20g has a significantly larger footprint.
I was reading about blind cave tetras, the site I found said they get up to 3" long, and can be housed in small groups in a tank of minimum 15g.
The frogs are an interesting idea, I hadn't even considered anything outside of fish - that's why I wanted other people's input, gives me lots to think about!

 

[chunksofpoooo]

Im so excited about getting dwarf puffers that i have to recomend them to everyone. They are really colorful if given enough light, so you wont have to worry about getting bright little castles or fluorescent gravel. Not to mention, their personality is so interesting. Every time i go to my lfs to check them out they rush up to the glass like little dogs, following your finger on the glass. You could probably fit a male and like 4-5 females in a 20gal, and the puffers love plants, so youd also have a good chance to work on your aquascaping skills. Ive never really liked big community tanks with lots of little fish, that's why i like the dp so much; you can fit quite a few in the tank, and they are one hell of a center piece

 

[Dawn Dansk]

About Dwarf Frogs

I have four African Dwarf frogs living in a little 5 gallon eclips(?). I love them! They can go with fish as long as no ones mouth is to big....

 

[Milky]

Thats one of my favorite books
it has all sorts of great
natural tank set ups i have a 29 gal
also i dont know what to do with it
its cycling right now i dont have
a stand for it.. ill probably use
it for my other tanks when certain
fished have to be moved or something