Prenatal Exercise DVD - what to look for?

I am hoping to find a good prenatal exercise DVD to use for the remainder of this pregnancy. I am not exactly a couch potato, but I wouldn't say I'm fit, either. I chase after four little girls, and climb a lot of stairs, but I'm about 20lb (10kg+/-) overweight. (after this baby... right?)
So, do you have any recommendations? Yoga? Pilates? Low impact aerobics? Something with a bit of everything? Anything I should stay away from? Do you have a specific title or person that you know is good? I'd love to have a little advice on this.
Thanks!

Bump! :)

I have a pregnancy dvd which I use and enjoy. As long as you get something that is designed for use during pregnancy you should be fine. I'm not sure if there are any pilates or exercise dvd's around though.

Fit to Deliver pre-natal pilates dvd is really good. You can google them - I used the dvd with both pregnancies and it was great.

Thanks ladies! I'll look for that title Nai and see if I can get it around here. I've heard mixed reports on most prenatal exercise programs - some say yoga is perfect for pregnancy (slow, calming, strengthening, etc.) while others say it overstretches joints and puts too much stress on the body. Same story for pilates - one says its the absolute best thing for staying toned and fit during pregnancy and snapping back to your pre-pregnant body quickly after birth, and others say that it's also too hard on the joints etc. :dunno:
I guess like most things, you've just got to use your discretion, and be gentle with your body. I just wondered if anyone was aware of anything that was particularly good or particularly bad.