Use the term Web 2.0 and you could get a nasty letter from lawyers representing the interests of O'Reilly Media, the Sebastapol, California based publisher owned by Internet 1.0 pioneer Tim O'Reilly, and CMP Media. The target for now, is an Irish conference organiser:

From Tom Raftery's I.T. views:

One of these events - the upcoming Web 2.0 half-day conference is the target of a cease and desist letter (below) from the legal team of O’Reilly publishers. Basically O’Reilly are claiming to have applied for a trademark for the term “Web 2.0″ and therefore IT@Cork can’t use the term for its conference. Apparently use of the term “Web 2.0″ is a “flagrant violation” of their trademark rights!

Ironically I invited Tim O’Reilly to speak at this conference last February and his response (which I received on 15th of February) was

I would love to be able to do it, but my schedule is just too full for an additional international trip.

So Tim was aware of the event in February but decided to wait until 2 weeks before the conference to set the lawyers on us.

As I mentioned, IT@Cork is a not-for-profit organisation and doesn’t have the resources available to O’Reilly - what do people suggest we do?

Bad news for the gazillion of me-too Web 2.0 startups out there. But great news for everyone that is absolutely sick of hearing the term.

At SVW, we prefer Internet 2.0 because this next stage of the Internet is about far more than web browsers. RSS, for example, has nothing to do with web browsers and all to do with Internet 2.0. There is no trademark on Internet 2.0. Jump ahead of the Web 2.0 pack and use the term Internet 2.0!

You can even use this catchy phrase in your business plan: Xyz.com moves beyond Web 2.0 and is an Internet 2.0 company.