One of the best ways to identify a bubble is to look and see if the smart money is leaving the market. People who know that the price is too high will want to sell out and earn some quick cash. But they have to be careful. If people see them selling, then they will know there is a bubble and the bubble might pop before the smart money can finish selling. So they have to use various means, from advertising to shills, to keep the market propped up. Since people can invent reasons to justify anything, the news will be full of people cheerleading the market and predicting higher prices. The price can creep ever higher as the dumb money piles in and the smart money sells.
I have seen a lot of signs that the smart money is selling gold. For example, today there was a big ad in the Wall Street Journal offering to sell the first ever gold coins produced by the Israeli central bank. In other words, Israel's central bankers want to sell off a lot of their gold. This is one of many examples.
In addition to this, I see no fundamental reason for gold prices to stay this high. The economy is recovering, which should reduce demand. The 'cultural Asian demand for gold' is probably a function of a historically undeveloped financial system; as their economies and institutions improve they should rely less on gold as a store of value. More and more gold mines are coming online, so supply will increase a lot in the next few years.
Now, the bubble could easily continue for a couple more years. Selling a house in 2007 would give you more money than selling in 2006. Gold could do the same thing in the short term. But selling a house in 2006 would be much better than staying in the market. And in the long term, real gold prices trend down, while house prices are about constant.
Basically, if you have gold hanging around that you are not using, my professional recommendation is to sell it soon.