There's a few people that are trying southwest themes, I haven't seen any pics yet but they sound interesting. I definitely prefer the "natural" look... To make it look real natural I'd have at least a few plants in there(live of course), maybe some driftwood and rocks... I'd also look for a natural substrate, not that colored gravel. themes and fish... it's a little hard for me to comment on because my taste could be way different than yours... Have you had any ideas yet as to a theme or are there any fish that you are really interested in? I'm thinking some plants and driftwood, maybe some khuli loaches... hmmmmm...... there are just too many ideas in my head now... you could have a hawaian theme with some lava rock or something and "mount wannahackalugie", you could do a tropical ilsand theme with sand as a substrate and a coconut shell decoration... lots of options... sounds like fun... just make sure it's something you will enjoy...