As for what cards have higher payout... here's a list I made so I know which card to use where:
# Amazon * 3x amazon.com * 2x gas * 2x restaurant * 2x office supply * 2x drugstore
# Chase Sapphire * 2x travel * 2x dining * travel bonus booked via ultimate rewards * no intl fees
# Discover (open road - apparently no longer offered?) * 2x gas * 2x restaurant
# Citi Forward * 5x restaurants * 5x entertainment * 1 point ~ $0.008
# Virgin * 3x virginamerica.com * 1 point ~ $0.024 towards flights
I also have an AmEx (blue) which has utterly crap rewards. I use it only for Costco and some electronics to get the extended warranty they provide. Other AmEx cards have much better payout.
So basically I use the Citi Forward any time I go out to eat, bars, bookstores, etc. While the points are worth only about 80% of most points, the multiplier more than makes up for it. Incidentally because Amazon is classified as a bookstore, it actually has a better return than the Chase Amazon.com card. If I'm buying anything that doesn't have an actual multiplier (which is fairly rare; most of my purchases are restaurants and Amazon) I put it on the virgin card since the points are worth over 2x what other points are worth - typical of most airline cards.
Australia limited interchange fees around 2003 (cut them in half), and as would be expected, merchants did not lower prices.
"Interchange fees are paid by the merchant, and there have been studies done in Australia that said that consumers have not saved a penny by lowering interchange rates — that the merchants have not reduced prices at all."
No, no ... no. The cost is not to "society", the cost is to merchants. They just earn less profit. (Think about it, if the cost wasn't to the merchants, they wouldn't care about credit card fees).
What cards are giving over 1% back? I noticed some other commenters talking about 2%. I just get 1% + the occasional special 3% promotion.