Before I got the stand for my 55 gal, I had it on the floor, and it was really hard to clean. The gravel sucker didn't do a very good job when it didn't have the gravity working for it. Also, I would like to look at them at eye-level.
I do have a lot of scrap wood peices laying around my house, but I'm not sure I trust myself to make something really structurally sound. So I think cement blocks are the way to go. I think I will just stack them in layers, one on top of another. . . Would cement blocks hold?