Whether talking to the most trustworthy hotel reservationist or the most incoherent Queens dispatcher, every guy's leery of repeating his credit card digits over the phone. When it comes to transpo, put your faith in shiny, anonymous HTML instead, with RideCharge.
Working with NY's largest Town Car fleets, RC stores your card's deets online, then lets you pay your fare by simply calling their service and confirming the charge, thereby avoiding reading your CC number to their dispatcher in advance, or leaving your bags as collateral as you scramble for an ATM. Simply drop your info (cell #, credit card #) and schedule your pickup online, and RC'll provide three pickup options and prices, which you won't studiously compare because you're expensing it anyway. Once the ride's complete, simply call RC, enter your seekrit pin, and RC'll charge the full fare to your card; the driver will then receive confirmation you've paid, but not confirmation of your miserly tip.
RC logs every pickup and emails every receipt, making for easy expense reporting and obviating the paper receipts you inevitably lose, making even the most incoherent accounting department leery of your trustworthiness.