Great ideas so far!
I've only got a 36" and a 12" cube, but want more. Unfortunately, we're moving house soon, so i'm going to have to dismantle them as I don't really want to have to move the tanks and get it all setup asap - moving house is stressful enough.
That being said, i've managed to convince the missus to let me get a 5 or 6footer for the new place, on the condition that i plant it up nicely! Winner!