CASTLECASCADE

Hi

1 general question and 1 specific question

1, Even after reading "RAM101", I am still confused about the difference between adding "bigger" memory and "faster" memory. Going from 256mb to 512mb increases system speed; so does going from pc-2700 to pc-3200 !!?
Then what is the difference between these two?

2, Now....I've been going far too long with 512mb on my HP system. Now I want to upgrade to maybe 2gb.
These are the specs of the RAM:
http://rapidshare.com/files/53176963/RAM_in_HP.jpg.html

Now there are 4 slots here. What should I get and what way should I arrange. Just give me one NICE suggestion.

....should i go for 4 slots or 2 slots ?
....is that DUAL CHANNEL thingy gonna work here ?
....what clock speed should I look for (ram101 faq seems written long ago) ?
....what i need is, i guess, "ddr2 sdram" ?
....should i think about VOLTAGE and LATENCY ?

These are the q's in my mind. I want performance increase in daily applications; browsing internet (dozens of windows); video editing; dvd ripping; photoshop etc plus some MID-RANGE games. And my system specs are:
http://rapidshare.com/files/53179062/CPU_in_HP.jpg.html (cpu)
http://rapidshare.com/files/53179460...in_HP.jpg.html (board)

And FINALLY, do you think this a TOO OUTDATED system (i am building another one right now; this is just the additional one)?

Thanx guyz..........