tat is absolutely myth, ur friend may not know much about hardware, but act like he knowing alot (just like Mr. Wall-talker).

u can use the 667mhz memory, but, from wat i saw in the technical support section, alot of user whose mobo (in ur case, laptop) support highest 533mhz ram, there faced problem with their RAM timing when use with 667mhz ram, and often cause instability. they finally have to adjust the timing manually.

my home athlon xp, the mobo only support 333MHz ram. i fix it with 1G DDR400 (OC the cpu and bus speed some more) and it run for a year plus already, but still alive and kicking.

for DDR2, i never try b4. but can see alot of user suffering some issue when they plug in higher speed RAM. but was solved when the timing was adjusted perfectly. maybe their pc will blow after sometime, shuld pm them after a year or 2.

majority of laptop BIOS cant adjust timing manually. in this case, i dont think it is a good idea to get a 667mhz for ur laptop, unless if u can bring it to the shop there and the shop keeper is kind enough to swap it with a 533 if the 667 couldnt work.

good for u. got test for stability?

u've got it http://www.memtest.org/, run it as long as u can. by the way, wat d u mean by TARPED in the interwub?