Wired on Friday: When you're stuck as an observer of the manic-depressive world of tech booms, you can often end up playing therapist. That's what I thought when I picked up two shell-shocked Europeans from the foyer of the Web 2.0 conference in San Francisco.

A new boomlet is beginning here, and that's not always a pretty sight. Unless you're part of it, of course. Web 2.0 is the handy label, quickly coined and affixed, for the rash of developments, investments and buyouts that are currently spreading through Silicon Valley.

This year's Web 2.0, the conference that originated the term, was the occasion for several of the more public deals.

In a single month, two of the old pikes of the internet bought out some of the spritely young tiddlers: the domain name magnate Verisign bought a site called weblogs.com and news aggregator Moreover. Yahoo bought Upcoming.org, a calendaring site to match its purchase of photo site Flickr and webmail site Oddpost.

While Web 2.0 is mostly about a handful of approaches to exploring and developing the latest advances on the web, it's these deals that are exciting the most press coverage. They're not IPOs, they're small start-ups, young and old, bought by larger companies.

Even younger start-ups and their venture capitalists have seen the sea change, and even now are trimming their sails to be a tidy corporate purchase, rather than a fast-growing potential public giant.

It was exactly that feeding frenzy that had scared the living daylights out of my European friends. They'd come to find out what was new: what technical tricks and innovations lay at the bottom of Web 2.0. What they saw, instead, was the froth on top: the marketing spiels, and the elevator pitches. The sheen of sweat on the cheap-suited prospectors, the preternaturally trim hair on the venture capitalists.

It's a shame to be intimidated, because there are some good, solid foundations to the new web - and some good opportunities too. (Moreover was originally planned in the UK.) Like Web 1.0, it's not entirely clear that those principles could be transformed to make money.

For many professionals, scarred by the mistakes made in the past 10 years, Web 2.0's principles aren't particularly profound, they're just obviously right.

Take "tags" - single keywords to describe objects. It's not a mind-shattering development in the history of ontology, but as a user interface and documenting twist, it seems to have a lot of legs online. On the other hand, if you want to catch an investor these days, it appears you need to have them - which is ridiculous.

Perhaps the strangest aspect to Web 2.0 is its determination, in the Google mould, not to be "evil".

Here, evilness has a geekish tinge, and accords with not being open, hoarding your customers data, placing tricks in their way so that they're locked into using your site (such as being unable to export your calendar settings to another site).

The reason is less moral than practical. If you're open to working with others, and to sharing your data, you quickly glean the greatest benefits from the open web.

You share your calendar information with other sites, and pretty soon everyone wants to use your calendaring application.

You let people know they can export their mail from your e-mail website to their home machine, and they become confident enough to keep their main mail account on your advertising-supported site.

Even more than before, these websites depend, desperately, on the goodwill of their users. And that's not just an exercise in good public relations: for much of Web 2.0, the "content" that will be monetised in these deals is the content supplied by users of the system. If the users turn, the data evaporates. Evil may be a hyperbolic term: but these sites do at least have to be nice - at least until they're a network monopoly.

Which brings us to their new owners. What is notable about these deals is the two mega-companies leading the charge to buy are, also, historically, notorious for their closed nature and unoriginal, dry pursuit of profit and growth.

Yahoo's sin for the last 10 years has been minimal: it's just been very self-contained and a little dull compared with competitors like Google.

But it has, until recently, been the archetype for the small company that lost its soul to an attempt to become a "media brand".

Verisign, on the other hand, has to be one of the most widely-disliked companies online. Master monopolists of the internet's domain name and its security certificate system, they've always been seen as a group who reached their $1 billion (€840 million) revenue from exploitation, rather than innovation, and gentle disregard of most of their customer's needs.

The distaste felt by my European friends, who drowned their sorrows in local wine and a pleasant vegetarian meal in another corner of San Francisco, was mostly culture shock, I think. The desire of everyone on all sides to make a deal in America and in Silicon Valley can be disorienting.

But the corruption of those little companies, with their big ideas, doesn't come in making the deal. And perhaps, as with the original web, the rightness of their ideas won't be compromised by the new company they keep - or, these days, that keeps them.