The first big city to boom was London, starting around 1996. Boom mentality spread to Los Angeles, New York, and Sydney around 1997, to Paris in 1998, to Miami, Moscow, and Shanghai in 2001, and Vancouver around 2002. These and other cities have been booming pretty much ever since; prices in most are up at least 50% in real terms since 2000. This has been a big windfall to homeowners, but has hurt anyone planning to buy.
Now growth in home prices is weakening in some of these cities. The rate of price growth in London and New York slowed sharply over the past year, to only about a 1% real increase in the second quarter of 2004. In Sydney, home prices actually fell in the second quarter.