I had my first u/s at 8 weeks and the heart beat was 176...
When I told my step-mum, the first thing she said: "It's a girl"...
going by her experience she had two girls with high heart beats, and her boy had a low heart beat.

I also had a palm reading done about 6 years ago and everything she said has come true... and the last thing she said/wrote was: 1 child - girl.

So I've just about convinced myself I'm having a girl... although I would like it to be a surprise if possible.
My husband really wants a boy... but with everyone telling him a girl he's starting to get used to the idea. He's got 7 months to get used to it being a girl... then I might surprise him & pop out a boy.

It would be interesting to do a survey with all the mums who have had kids... find out what the most popular heart beats were for boys/girls...