Ron Friedmann of Prism Consulting put together an excellent presentation on why law firms should use blogs: Blogging: Why the Fuss?
I have been trying to convince my marketing group to convert some of publications into blogs. The hang up seems to be trying to put together a blogging policy and branding (beyond the typical concerns about learning a new technology and attorney concerns).
I set up an example blog using Blogger in a few minutes and transfered over a substantial amount of content in a few minutes. Since it was Blogger it was free.
Cheap and easy is my kind of project.