I'm not sure exactly what kind of DDR ram I've got right now, but I wanna add another 512 of PC 3200 is it ok to use that if my other 512 is like pc 2700? Also, is there any way to find out what kind I currently have? it's not printed on the ram.

find the system specs from somewhere. get the numbers on the ram and run them thru google, that mite help. i dont think its a good thing to run 2 diff types of DDR ram like u are suggesting.

There will be no problem using two different speeds of ddr ram together its just that the faster speed ram will just clock down to the slower ram thus there not much point paying more for the faster speed unless you are planing on some sort of upgrade in the future or thers is no price difference upon purchase

Alright. I guess it'd be best to go for the PC 3200 and then upgrade at a later date. Is there a particular brand that you would recommend, or are they all pretty much the same? Last question: if I buy some ram that doesn't come with a heat spreader, should I buy one seprate? DOes it affect performance much? Thanks for the help!

Read an article once. Absolutley SLAMMED heat spreaders. Said they did little to nothing. Also, if you buy ram with heat spreader already on it, chances are it has already been over-rated (some ddr266/PC2100 being sold as ddr333/PC2700 in old days!).