In looking for numbers on the presence of lawyers on the internet, I came across this post at stemlegal.com. It provides the numbers of members in the Law Practice Industry category at LinkedIn as of June 2009.
Steve Matthews, the owner of stemlegal.com, also has a lot of good stuff on this blog about online marketing for attorneys.
Establishing a presence on LinkedIn and updating/connecting regularly is a lot like offline networking, and is a good way to start your presence online if you have no website.
Vivian