I think this is a great Idea. It is similar to the idea of a wiki but possibly more integrated into the forums since the wiki never kicked off
Here is another one of which card to use for what? Here is a quote from Dan.
"My current strategy is :
-$25+ purchases (including car rentals due to primary CDW), and foreign purchases, excluding dining, airfare, hotels, telecom, cable, office supplies, 5% category, gas, Open Savings Partners, and Gap Inc purchases on United Club.
-Purchases under $25 and 5% categories on Freedom.
-Dining, airfare, and hotels (including foreign purchases in those categories) over $10, and car rental in Israel goes on Sapphire Preferred WMC.
-Purchases at SPG hotels as well as purchases that I want warranty, return, dispute, or purchase protection on goes on Starwood.
-Open Savings purchases go on Starwood Business.
-Hyatt purchases on Hyatt.
-Telecom, cable, office supplies (including gift cards for Amazon, etc), and gas on Ink Classic.
-Gap Inc purchases go on Banana Lifetime Luxe.
I don't have an AMEX PRG right now, but I'll probably shift airfare and groceries there when I get my next one."