Please leave me a voice mail...
I remember in law school during my professional responsibility course that the main reason that lawyers get reprimanded by the bar is for failing to keep in contact with their clients. Thus, I am very diligent about returning phone calls. In addition to giving them my office number, and email I provide them with my mobile phone number. I am also available via text messaging, gmail or google talk.
For some reason however, there are still some people that still refuse to leave a voice mail or use one of the other methods mentioned above. My assistants are taught to encourage my clients to leave a voice mail or they make sure that my client has my cell phone so they can reach me if they do not want to leave a voice mail. Of course, if the client refuses to leave a voice mail they will take down their information. The problem arises when it is a time sensitive message that needs immediate action. There are other times that I am in trial or out of the office and do not receive the message until I return to the office.
The bottom line is if you really want to get a hold of me leave me a voice mail. I promise that I will return your phone call promptly!