This kind of question is often brought up on Slasdot . One good suggestion I have seen is to run conduit to the rooms, so that as new technology comes along, you can blow new cable/fiber/whatever to wherever you need it. This may not be so necessary though, as wireless seems to have a pretty bright future. Also, having a dedicated wiring closet for all your CAT5 and RG6 to end up in would be a nice feature.