If you find your gaming experience limited by your hardware or prefer your action to be more fast and furious with every new release, then you might find SpeederXP useful.
SpeederXP accelerates various aspects of your PC that in theory, should improve your gaming experience. This includes mainly your graphics card for games that demand a lot from it, your CPU for those that hog your processing power and your internet connection for those that are played over a LAN. In reality, if you're a serious gamer, you'll have a pretty decent setup and won't require SpeederXP to help you. However, if you are working on a slightly older system, then you will undoubtedly notice an improvement in the speed of your system.
How much SpeederXP improves your gaming though depends on the game. Some users have complained that the program can lock up their system (probably due to overclocking) but in general, it does seem to provide at least a 20% boost to gaming speeds whilst it works. The slower your system, the more you will notice the benefits of SpeederXP, of course. On a fast system, you will barely notice or need any of this. SpeederXP operates via a throttle which the developers recommend cranking up to maximum although if your experience instability problems, you're best to leave it at a happy medium point. The program is updated regularly automatically with improvements although you need to pay to upgrade and receive the unlimited version.
SpeederXP is a handy little utility for gamers on slow systems although serious gamers with decent equipment need not apply.