Here is the posting I put up on the 'Missed Connections' section of Craigslist a few days ago:

"Please Help this guy! "This Guy" being Me.
My phone is riding around the city right now with no way of getting home. I just got back from spending the holidays with my fam. and I took a yellow cab from LGA to the Upper Upper East Side, today (Thurs. Dec. 30th) around 3:15pm.
As many of us do now-a-days, I use it as my ONLY phone. So, I have no way of calling it to see if anyone answers. No way of calling my friends to ask them to call the cab company. blah blah blah...
basically, if you happen to see a small, sand-colored, (NON-flip) Nokia in the back seat of a cab, would you mind calling one of the numbers in the contact list? or better yet, respond to this listing.
You would be recognized as a very cool person.
- thanks"

Yup, that sucked. In a desperate state, I borrowed a phone from not the new neighbor across the hall whom I haven't met, but from his old college friend who was staying over that night and was the only one home. I was able to get in touch with a lovely female fashion designer/soccer dynamo who I was to meet later, and she vowed to keep trying my phone#. When I saw her, she shared the splendid news that one of the times she called, the cab driver actually answered the phone. He unsuccessfully attempted to get her out to Queens to pick it up personally, but he was eventually persuaded to give us a call when he was in the city the next day.
He did so, dropped by my neighborhood, handed me my phone, yelled at me for leaving it in the cab, scowled at the $10 I offered him for his troubles, and drove away.