Google hit $170 a share today, doubling its IPO price of $85. The company announced quarterly results that analysts called a "blowout."

Prudential set a $200 price target on the stock.

While many feel dot-com deja vu over the vertical rise of the stock, the big difference is that Google is hugely profitable, with real earnings and cash flow. Google has a "nasty habit of making pundits pay" for their short-sighted analysis.

Lookout Microsoft.