Somewhere there is a thread about Intelligender....my opinoin only, of course, but from what I've read here and on other forums, you have just as good a chance of asking some yahoo off the street what the gender of your baby is and them being right as you do with Intelligender accurately predicting your baby's gender.
I know that 20 week wait is agonizing but if it were me, even if Intelligender told me the gender I was hoping for, I'd doubt it anyway until the ultrasound so I really wouldn't be gaining anything, KWIM?
Good luck and I hope you someone returns your calls/answers your emails soon.