Here's a great tip from reader Jenny, who's found a way to model her new apartment's layout using free software from BoConcept. Says Jenny:
..."it lets you do a room layout, multiple 3D views, and then you can do a virtual 3D walk-through of your room. You are limited to the furniture provided, but most of it is fairly modern and generic. On top of that, you can change finishes, flooring, wall color/type. When you're done, you can print it out all to scale.
I call it my "virtual dollhouse" and have been having fun trying on different pieces of furniture and for trying different room arrangements. And it's free!"
There's no version for Mac. Boo!
Some alternatives can usually be found at Half Price Books in the $5-15 range, if you want furniture options other than modern. I haven't tried any yet -- I'm still using a 10-year-old edition of Sierra Home Architect, which also allows you to upload photos of actual furniture. Some packages have free/cheap online access to even more furniture and patterns, too.
None of these little cheapies are powerful enough to do real architecture, but they're handy for testing theories of where your furniture might fit or whether an accent wall would make you crazy.