The performance boost from dual channel RAM is negligible at best. With a max capacity of 3.3GB, you're best off just buying 2GB or 3GB of RAM and save yourself some money.
i agree with you that the boost performance is "negligible at best". however if you combine that small performance boost along with the extra 300mb of ram your not getting by going with 4GB over 3GB then i think it does make a difference and for the "negligible"
price difference you might as well get the added performance.
not arguing with you Kash
just i think the extra 300mb would make a difference and the price difference from 3 to 4GB is small.
of course if your your not running windows on it , or using graphics software, etc... and all you do is surf, email, itunes, IM, etc... then save yourself even more money and go with the 2GB deal because that will more than work for ya.
FYI- i run occasional photoshop etc.. as well as windows XP (via VMFusion) and sometimes both at once with only 2GB of ram on my macbook and i rarely ever max it out. my guess by the way you worded your question is that 2GB kit would be more than enough for you.
good luck