I've been looking for one of these for a while, too, although I haven't looked too hard.

My guess is that in the city, bodegas that cater to cab drivers will probably have them.

Also, for anyone looking to order an EZ Pass, you don't have to get it from Delaware to pay no fees. If you click through the MTA website and link a credit card to the account, there are no fees (you are charged $25 to top up the account when you sign up, but you can use it all to pay tolls and there are no other deposits or fees). If you order directly from one of the EZ Pass websites, however, and put in NY or NJ as your home state, there is a $1/mo "PANYNJ account service fee." So make sure you click through the fee-free link. Compare section 16 of that page to section 16 of this page and you'll see that the first one doesn't have the $1/mo fee. I can confirm this works (I've had my MTA-issued EZ Pass for over a year and have not been charged for anything but the tolls I've gone through).