What's dangerous? Plenty of investors seem to hope that history repeats itself, so they're buying the strongest survivors of the dotcom bubble, including the three quality tech warhorses named above, ignoring valuation. In fact, many tech stocks have surged to valuations unseen before, except during the bubble. While the bubble survivors are likely to remain viable companies and thrive in a healthy economy, their stock prices do not reflect their earnings prospects. Intel, Microsoft, Network Appliance, and quite a few other tech companies trade at multiples that imply far more growth than is realistic. While that's worked for those...