Printing Buildings
This is not the first time I'm reading about this; some five years ago I remember reading a related article online or in IEEE Spectrum. I'm somewhat hopeful that the technology will mature soon enough for mainstream use and will be affordable in the parts of the world that proper housing is desperately needed (e.g. Africa, India).
It goes without saying that the newly found ease of building should be accompanied by renewed building regulations in order to avoid cases where buildings appear 'overnight' without any building permits authorising their construction. Another concern might be whether architecture could be compromised by the technology in the long-term leading to the replication of a single or few designs destroying the feel and character of cities or regions.

Excellent talks on hard drive data recovery by computer forensics and data recovery specialist Scott Moulton, for those that feel confident messing with their hardware. Extremely informative and very useful especially in those cases where you'd like to salvage your data from a broken drive, but don't want to shell out ~€2,000 for a professional data recovery company to do it.
Two lectures, one from DEFCON 14 (2006) and another from 15 (2007). There's some overlap, but they're both interesting to watch nevertheless. Around 45 minutes each.
Hard Drive Recovery (at DEFCON 14): Parts