I'm currently running a HTPC based on a AMD Athlon 64 X2 4850e on a 780G based motherboard. All media is stored on a NAS. This setup works great for 720p, but it's not as silent as I'd like.
I've seen a few postings about XBMC on BeagleBoard, but it doesn't seem to be in a functional state as of yet.
What I'd really like is to have a passively cooled box that's able to play 1080p H.264.
Given a proper infrastructure in the surrounding area, tall buildings can certainly lead to a more efficient transportation system. When a building reaches a certain size however, the transportation system inside the building starts to become a problem. How tall can a building be built before all the space gets eaten up by elevator shafts?