This is a link to a program called Latency Fix, initially used for World of Warcraft, but works for most other games, I use this is APB Reloaded as they don't have Australian servers, and anything helps.
It works by increasing the frequency of TCP acknowledgements, or in simple terms, reduces Latency/Ping.
This could possibly give you that slightest edge on other players, unfortunately I cannot give an example as every patch APB Reloaded servers get worse, however there is a definite improvement that I have seen.
You do need to restart your computer for it to take effect.
This is Game Booster, and works by stopping services and programs that are not needed to run windows or your specific game, and you can make exceptions, it frees up RAM.
This allows for better performance client side.