The last time a big tech company went public without having to, its name was Microsoft.

The famous story from that IPO is of Steve Ballmer and Bill Gates, still young and tight with a buck, forced to fly first class to New York for the event, using the in-flight phone on board to rag their investment bankers about the money they were wasting.

But the Microsoft IPO didn't really challenge the way Wall Street worked. Gates' bark was worse than his bite.

Google's IPO is quite different.

First, it's going out as an auction. Google has set an amount to raise, $2.7 billion. It will offer only enough equity to reach that figure. Investors will file for shares, and offer their best price. Then, underwriters Morgan Stanley and Credit Suisse First Boston will go through the bids, until they find a price that, when multiplied by the shares on offer, meets that figure. All the "winners" will then pay that price.

There's no guarantee that the stock will pop after the IPO. Google will collect the maximum sum it can from investors for the minimum equity dilution. But insiders won't have an inside track on these shares. If you bid high and your bid is accepted, you'll get your shares at the market-clearing price. This makes the auction a great deal for Google, but also fair to investors.

Second we have the S-1 itself. While most such filings are dense and dry as dishwater, the Google filing is more like Warren Buffett's annual letters to his Berkshire Hathaway shareholders. It is written in clear English, and states exactly where Google hopes to go with investors' money. It describes the business, describes how it works, and describes how it's changing. It's that rarest of things, a good read.

Third, we have the management. Founders Sergey Brin and Larry Page remain at the helm, along with Eric Schmidt, the former Novell CEO they brought on for "adult supervision." They've also beefed up the board's credentials with Stanford University president John Hennessy, Genentech CEO Art Levinson and Intel COO Paul Otellini. But just as Gates and Ballmer stayed on top of their pyramid at Microsoft those years ago, so Brin and Page will stay with their company.

The auction, the document and the control exercised by Google's founders are all a direct challenge to the way Wall Street has traditionally done business. This deal could shake Wall Street to its very foundations, especially if Brin and Page squeeze the maximum possible from investors with the minimum payment to their bankers.

Great Googly-Moogly.