My parents got back from a whirlwind trip to Canada this afternoon, and we thought that since their visit here was scheduled before we knew Sarah was pregnant, we thought one small way they could participate was to come along to an ultrasound screening that determined the baby's gender.
So we lashed out on one of those gimmicky 3D/4D ultrasounds, and didn't tell Mum and Dad what was going on until we got there, so as to make it a bit of a surprise for them. I think Dad thought we were going to see a baseball game, because when Mum asked what to wear, I told her it didn't matter, and that it was a spectator activity.
I called it as a boy before the sonographer made a call. She initially thought it was a girl, but revised it to be a boy as the scan progressed.
I'll update this post with some of the images later.