At 18 weeks husband and I were too excited and couldn't wait for the doctors ultrasound so we went to UC baby just around the corner from my home...ok we paid $200 for it (pretty expensive), but it was the BEST experience!
We seen the baby on a big screen moving around and sucking his thumb it was soo cute. Finding out it was a boy through that experience was amazing. We also got 3 print outs and a whole CD of pics of our little man. So I'm now telling friends to do the same to find out the sex of their babies instead of finding out through the cheesy lab machines. My opinion only of course :) But husband and I were happy we did it, and would do it again for later pregnancies :)