The Xerdict Group (legal tech consultants) point out reasons why large law firms are not the only ones to find extranets useful. Here's an excerpt:
I also know of many instances when small law firms (firms with less than five attorneys) use legal extranets for a different reason. The reason is that they totally outsource to an ASP the ability to manage tasks on-line, posting of documents that they wish to use while traveling, putting up simple case calendars and status reports for clients, and many other pieces of data.This use is far less about collaboration, and more about providing small firms with little or no IT department a way to web-enable key data and documents.