That's easy - Icovia (http://www.icovia.com). They have a free edition.

We have to move to an apartment that we are renting sight unseen. I have the apartments rooms dimensions, as well as a general floor plan. Is there any software or a website that you all can recommend that can help me map out where my furniture might go and be able to visualize it? Like I could plug in the square footage of each room, and it will show me what a queen bed would like, or a sectional, etc.?