I currently have X2 sticks of 512mb ram.(pc 2700 184 pin ddr). and i was wondering if i could put in a different pc# ram like pc 3200. thx:
Yes. RAM speed ratings are like a tire MPH rating. You may have tires good for upto 150MPH, but you may only drive as fast as 60MPH. You're not going to hurt yourself going slower than 150MPH, but you're not using them at their full potential (and in this case, it's probably a good idea, unless you're a race car driver). Same thing with RAM. It will function fine at a slower speed. However, don't expect your PC2700 to run at PC3200 speeds. They still may be able to, but they're only guaranteed PC2700 speeds, especially if it's not enthusiast-grade RAM (ie. Corsair XMS or Patriot +XBL).
Note too that if the motherboard's maximum FSB speed is 333MHz, then putting in PC3200 (400MHHz) will be of no help as the RAM runs at FSB speeds and no more. So, check your motherboard specs and see what it supports. Having said that, I agree with Big B - PC3200 will toggle down if put in a slower environment. SO - if you are looking to buy new RAM, and SOMEDAY may upgrade to a faster motherboard, then buy the faster RAM now and then you won't have to later.