Yoga or Pilates?

As part of my 2011 1/2 goals (till June) I told myself I would start up yoga or pilates to switch it up and help with my strength and flexibility. To adhere to my goals, and hopefully to prevent any more injuries, I think its time to start something up.
I'm going to be honest- I have NEVER done EITHER- so I have no idea what I will be getting myself into. I would like to start something up when I return from Disney and get all moved in ( around 3/7)  To any of my blogger friends:

What do you recommend for someone just starting out?

What do you prefer and why??

Any helpful tips / suggestions for a beginner?