Yea. Unless you have the luxery of having an "upwards-unlocked" processor, the only way to up the processor speed is to up the FSB. The memory can be locked or put on a divider with a capable mobo, but with a SocketA, that will hinder performance.
I know that "OC-ing" RAM is expensive, I would seriously look on Ebay. Thats where I got my stuff from. If you have an NForce2 chipset on ur mobo, you`ll be able to take ur 3000 up by... 2-300 MHz, but a good choice of RAM now will let u do more with it later.
I`d personally recommend low-latency PC3200 (esp. Corsair or PDP) or low to mid-latency PC3500 or PC3700. PC4000 onwards should only be bought if the price is silly low. Most PC3500 and 3700 memory can be taken to PC4000 speeds if you`re willing to play with memory timings (even if ur not now, from ur post ur happy to overclock, so in the future, u will become so!) so one day, when u need to, u can overclock ur memory and see another performance gain
Kenny.
Any questions, just ask. I`m a pretty sad, committed overclocker. lol