i've been offered a laptop with intel x3100 graphics...

it's a Toshiba Satellite dual core. just need to know if i'll be able to run SL on it? i don't care if i have to put XP, Linux or even Mac OSX on it (either way Vista is coming off!)

No, dont touch a Intel vid card if you plan on doing anything in SL, unless you want 1~7 fps top.

Intel vid card is abysmal no matter their numbers, and drivers is quite hell to get it working if SL decide to choke on them.

SL recommends these and i sort of agree except i wouldnt say ATI, to much issues with opengl.

Ati : X1600, X1900, X2400, X2600 or higher
Nvidia :6800, 7600, 7800, 8800 or higher

http://secondlife.com/corporate/sysreqs.php

fps is not a problem, so long as it runs without crashing

It will crash and often, Intel cards dont like opengl at all, if you got lucky and got it working, it will crash i guarantee you on the next SL update or a fix soon enough so its not worth the hassle.