On March 10, 2000, the Nasdaq composite index closed at an all-time high of 5048.62. Shortly thereafter, the stock market bubble burst, dropping the Nasdaq composite down to an intra-day low of 1108.49 on October 10, 2002, a drop of about 78% in just over two years. In the subsequent rally through today's close of 2262.04, the Nasdaq composite index has risen about 104% from its 2002 low. However, it still remains about 55% below its all-time high closing value.
CNN.com has a nice article about the 6-year anniversary of the Nasdaq composite's all-time high close.