I've tried this and not only does it save money and petrol, it makes your driving much smoother as well. Instead of revving the engine at the lights just to get up to speed and then braking again in about 10m for another red light just wastes a ton of fuel. And by braking, its as good as dumping your fuel into the drain because you're just wasting the fuel that you used to get up to speed. So using the brakes less and controlling that heavy right hoof of yours will save you fuel.
Of course you won't be going as fast but then again, why do you have to? On the expressway, maintaining a constant speed and watching out for cars braking far ahead will keep you from braking unnecessarily because you can lift off the throttle and cruise without wasting any petrol. On roads with loads of traffic lights, maybe just accelerating gradually instead of flooring the pedal could help retain some cash in your wallet.