I was exploring my AMEX account online and discovered iDine. I signed up for free and discovered that there are several kosher restaurants in the LA area on the list!
Charging it to your registered Amex card will get you a 5% benefit back.
Here is what I found:
All Fish Grill locations in LA area...
Tierra Sur @ the Herzog Winery
The Cafe (Pico area)
PS Kosher Food (catering/takeout in Pico area)
I then searched Brooklyn and 11 came up!
You really need to look at the whole local list as Fish Grill wasn't listed as a 'kosher' restaurant even though we all know that it has a reliable kashrus certification.
Good luck and let's start a list perhaps!