rats- just lost a bunch of links that I found. anyways, google search pictures for turtle tanks and such. A lot of them are... plain for lack of a better word. Honestly, turtle tanks are usually bland imo as not much can survive a turtle unless the turtles have a garden and small pond to themselves. Which is awesome btw. Great for areas that have nice weather year round.
Anyways, I used to keep a red-eared slider, but her tank was simple and quite dull. Something I find rather distasteful in turtle tanks. However, these examples I've found (google's amazing lol) might help you find some new inspiration than the pictures on petstore sale adds.
anyways, here are some ideas that may get you started:
a nicer looking turtle tank. lovin' the green.
different tanks- turtle tank near the end. there's also a "pond" tank that may interest you... not sure on the size of your tank though.
tank pics
very pretty. not very practical, but perhaps a few fake grassy plants would work in a corner with some rocks or something like such.
This is a collection of a couple of different tanks. My favorite is of course the naturalistic turtle tank. BIG rocks =

I believe there are links to other areas with more pics under the naturalistic tank.
enjoy!
inspiration perhaps?