INITIAL public offerings. Big takeovers. Nerdy 20-somethings getting rich quickly. To borrow a phrase from an old Prince song, the markets are suddenly partying like it's 1999 again.
The tech bubble is back. Facebook is commanding an enormous valuation. So are Groupon, Twitter and LivingSocial.com. Even Rovio Mobile, the small Finnish company behind the hit app Angry Birds, looks like it will soon be worth a fortune.
The trouble is, everyone still remembers how the bubble burst last time around. Investors know there is a lot of money to be made from technology. They also know there is just as much to be lost when the bubble bursts.
To steer a way through that -- backing the winners and avoiding the obvious calamities -- there are some simple rules we should draw from the last tech boom: Don't worry too much about business models; look for emerging monopolies; back the greediest entrepreneurs; and buy after the hype subsides.
That way, one should still be able to make money out of what remains the world's most lucrative growth industry.
There is little question that some verve and excitement have returned to the technology markets. It might not be quite back to the levels of mania that surrounded the dot-com boom -- but it is getting close.
Facebook is valued at $50bn (€35bn), on the basis of its most recent stock sales. Groupon, the Chicago-based daily-deals site, has held talks about an IPO that would value it at as much as $25bn (€18bn), according to people familiar with the matter.
Its competitor, LivingSocial, may follow it to the market. Twitter valued itself at $3.7bn (€2.6bn) at the end of last year, and may be worth a lot more by now.
AOL, a company that knows a fair bit about internet bubbles, has pumped some excitement into a moribund media industry with its $315m (€222m) purchase of the Huffington Post website.
Even humble app designers are now hot properties. Rovio Mobile is preparing itself for an IPO, and last month received $42m (€30m) in funding. At this rate, it may one day overtake the fallen star of the Finnish tech industry, Nokia.
Not everyone thinks it will end happily.
"Most of them will be overpriced," said legendary investor Warren Buffett about social-networking valuations last month.
True enough. Among investors with a memory stretching back more than a decade, the simple combination of words "tech" and "IPO" conjure visions of valuations spinning out of control -- and everyone losing a fortune on a lot of companies that, looking back, were about as solid as a bowl of chicken broth.
It is certainly possible that this tech boom will end up with more Angry Stockholders rather than Angry Birds.
Against that, the likes of Google, Amazon and Apple are now among the biggest companies in the world. The internet economy is expanding all the time. If you invested in the right businesses last time around, you made a lot of money.
So the trick is to back the right horses -- and to do that you need to learn the lessons of the last tech bubble to ste-er your way through this one.
Here are four good places to start.
Likewise, we go to Facebook because that is where all our friends are. So it's best to look for sites or software systems that everyone flocks to -- not because they are necessarily that great but just because everyone else does.
Technology is where the real fortunes of the next decade will be made. Investors just need to make sure they tread carefully -- because there will be some spectacular turkeys out there as well as some great businesses.
Matthew Lynn is a Bloomberg columnist