Here in the US you can buy an over-the-counter gender test called IntelliGender; they sell is at Riteaid and a couple other drugstore chainrs. I think it's about 90% accurate. It accurately predicted a boy for me at 8 weeks pregnant. I was still dying to have my anatomical ultrasound, though, to confirm the results!
One thing they say about boy pregnancies that was true for me: I craved lots of salty and tangy/lemony foods, wasn't really interested at all in sweets.
omg I had no idea this thing existed. I would surely have bought it with my second pregnancy when I was just dying to find out what I was having.