SJ - wow, you definitely asked the right ladies about when to weigh!
I'll throw my 2 cents in too
Although my weight loss hasn't begun on this time around, I know that past success came with weighing once a week. There are definite ups and downs to all of it.
Ups: you don't see the daily fluctuation. Bloatedness at night will affect you differently than when you wake up the next day. For instance, i weight 183 yesterday morning, 183.5 last night, and 181.0 this morning. (I knew my short weight obsession would help today!.. now I can advise

) But I didn't eat anything last night and all I did was sleep between the 183.5 and the 181. But, in 6 days I'm weighing in for real and I'll adjust my sliding bar to reflect it. Fingers crossed that it goes down!
Okay, I rambled. In a nutshell, your motivation won't fluctuate as much if you weigh weekly. You won't see the natural body fluctuation and you won't take it the wrong way.
Downs: You may not lose every week either, and that can get depressing also. If you're good at keeping track of menstration, you may realize that your weight may not go down as much, or at all, when you're on your period or right before. If you've waited an entire week to weigh in, and you don't change, it stinks. But, if you stay good, even if the scale gets stuck on a number for awhile.. it'll move if you keep working at it.
I would say get on as much as you want, but only take it seriously once a week. Also, pick the day of the week that works best for you. I like Wednesdays... two days afte rthe weekend to get things toghter, two days before the weekend not to blow it again. I won't weigh in on Monday if I've slipped a little (even by just having some beer) on Saturday night. And if I weigh in on Friday, I'll blow off the entire weekend knowing that I have until next Friday to lose it again. So, Wednesday it is in my house! (Okay, but this week I forgot so it was Thursday). Okay, so Wednesday or Thursday in my house!
Either way, don't do the two month thing. You'll 1) go nuts, and 2) if it doesn't meet your expectations, you may get discouraged.
keep on truckin! and don't be scared of the scale.
