Although I don't have pics, in my old 125 gal reef, I got two pieces of live rock both of which happened to have a a good right angle on them. So, I put them on top of each other to form the corner of a stone wall. So it ended up looking like the footing of a wall of an ancient greek ruin. Everyone who saw it thought it was really awesome, especially after the coral had grown in.
IMO, its a matter of scale. I don't think a 7" tall column is feasible at all, who would build such a thing? Its sooo fake. But, if you find stuff that is a bit larger scale to put in your tank, it ends up looking like a nice blend of humans and reefs. For example, instead of a 7" diameter ship's wheel, why not get a larger one and cut off a quarter of it and put that in the tank so it looks like a very shallow fringing reef that grew off of an errant ship's wheel...