Of all the ridiculous ideas that precipitated what people are apparently calling The Great Recession, junk mortgages -- "subprime" is somehow too kind a word, here -- have to rank among the worst. Real estate in general, and New York apartments and condominiums in particular, have long ranked among the smartest and safest investments out there, but the rise and sad popularity of junk mortgages such as "interest-only" mortgages during the real estate boom did much to unmake that. Sure, the right NYC condo is still a terrific investment, but the market in general was damaged seriously by all the homes and apartments (generally not in New York City, of course) that were sold to people via frankly crappy means such as interest-only mortgages.