I forward my office phone to my mobile phone. This ensures that I can take calls no matter where I am at in the world. That was until I gave up I had my old Blackberry with Verizon Wireless. Once I got iPhone with AT&T, however, I noticed that I have no access in my office. So, ironically, I can take calls made to my office anywhere in the world, except when I am in my office.
Solution: My office phone rings once before it forwards the call to my mobile. Of course, my mobile phone does not even ring. So, when I hear my office phone rings, I run out from my office to the hall way, hoping that I can get the call before it goes to the voice mail. Most of the times, I am not fast enough.