Yeah you might as well weigh the nearest book to hand, as opposed yourself if your weighing daily for all the insight you gain from it.
I weighed myself yesterday and had STS since Tuesday, so thats all of wed and all of thur and all of fri, perfectly sticking to plan - and STS... then I weigh myself today having drank some water and feeling a bit bloated and i've lost 3ibs....
Definately only weigh once a week - that's what i've learnt!