Have Separate Work and Personal Cell Phones
Refusing to answer personal calls during work time (barring emergencies, of course) helps you get your work done sooner–and it emphasizes to your co-workers that you’re committed to your work rather than letting the outside world distract you. On the home front, that means that your colleague can’t, in fact, call you at home while you’re at the dinner table with the family—or at least, with a separate phone, you can choose not to answer the call.
Get it done: If your company doesn’t provide you with a separate work phone, try Google Voice. The free technology allows you to create a different phone number to give to your work colleagues as your “cell number”; the number will forward to your cell phone as usual, but you can program your phone to ring differently when you get a call from that line, and turn “off” that number, sending everyone to voicemail (via ‘do-not-disturb’ enabling) after business hours.