very good point ScorpiNo, in addition to interesting, it also will help reduce the amount of the sand bed that will become stagnant from having rocks on it. What I have done is get some taller rocks with a relatively narrow footprint and space them apart a the proper distance to prop a nice 'shelf' rock across them.

** Buy some egg crate and lay down on the bottom of the tank to help distribute the weight of the rocks if you choose to support a large weight of rocks on a small footprint. this will help distribute the weight more evenly **

In general, know your budget... if you can't break the bank on your saltwater hobby, then adopt the ideaology 'less is more'. A small, well designed aquascape that is filled with coral will look better than a very large aquascape sparsely populated with coral. If you go with a smaller aquascape make sure to add lots of actively swimming fish as 'filler' to keep the aquarium visually interesting. I have found that a school of chromis is an inexpensive way to add lots of movement, and at the same time accent the size of the larger show fish.

reef keeping on a budget ... seems like that should be a logical fallacy