I've been in Cape Cod the last couple of days with marketing staff from US legal firms, courtesy of Hubbard One. And I've seen the familiar pattern of a handful of firms who get web 2.0 accompanied by a majority struggling with the very concept.
Some examples (mostly borrowed from a presentation by Hubbard's Chris Kraft):
Structured search
This is the idea that you provide users who go to the bother of using your own search with something a bit more than that they could have got from Google. Best example provided was Skadden.


Video
DLA Piper's 2008 Real Estate Summit was singled out for praise on the basis that extending a fixed location event to a virtual audience was a smart way of amplifying the benefit of setting up the event in the first place.
Social Networking
Last year London firm Allen & Overy attempted to ban access to Facebook for its London employees but later had to overturn the decision following a backlash amongst staff and the media.
Lawyers turn out to be prolific users of social networking sites -- a fifth of registrants for Reuters' own Carbon Community are lawyers.
Sharing
The twin web2.0 concepts of syndication and sharing seem to have made few inroads into the legal profession. The only example of a reasonably solid sharing palette was from an Australian firm -- Deacons.

Blogging
In a March 2008 survey it turns out that 53 of the top 200 law firms as measured by AmLaw were blogging -- a third of those having started in the previous six months. That puts lawyers somewhere between the fast-growing companies of the Inc. 500 and the Forbes 200 charities (according to research from the University of Massachusetts).
The overwhelming majority of those in Cape Cod were blogging and this did look like the area most likely to see real progress (there is a term for a legal blog that I hadn't been familiar with 'blawg' and there's a site called blawg.com that is indexing more than two thousand of them.