I was going to redecorate my home theater...I am waiting for the axiom inwalls to arrive and was thinking of building columns on each side of the screen and perhaps installing the axioms into the column. would there be any downside to this?

Are you referring to the W series speakers? If so, then installing them into a column may not be ideal. They were designed with the assumption that there would be a flat wall to either side for some distance. I'd give them a call to be sure, though.

How about installing them in a 4' high column, that sits on rubber pads or spikes so you can move it around as needed.

ooh wait. Thats already been invented. It's called an M60 or M80 or something...