Not to belabor a point, but as I mentioned in an earlier post on “marketing continues after client hires you,” it is good marketing to give your clients your home and cell phone numbers. I realize this suggestion would not apply to every practice (criminal law, for example) or to every client, but if a client is important to you, there is no reason, that I can think of, for not giving your home and cell numbers so the client can reach you at any time. Yes, any time the client needs to (you can always turn it off, if you are doing something just too important, such as playing squash or whatever).
A post on The Great American Lawyer blog also suggests giving your cell phone number to clients. It reminded me of just how important communication with clients is, and when a client needs to make direct contact with you, having your cell phone number is probably the most important number a client can have.