I believe it's called aquascaping, being underwater and all
I use these two sites for my main inspiration: http://www.adana-usa.com/index.php?main ... _portfolio and http://showcase.aquatic-gardeners.org/2009.cgi
But also I get alot from the artists personal websites and tank journals on other (international) forums.
HTH
(The first link takes a while to load for me)
Ninja'd by N1CK