Netflix has added the ability to control the quality (and data usage) of your Netflix streaming, helpful if you have a capped bandwidth account or are using a mobile device. Netflix added a similar setting for Canadian subscribers in February when ISP's up north started capping bandwidth.
You can access the Manage Video Quality settings under Your Account:
"We know that some of you have Internet data caps and we want to make it easier for you to manage how much data you use. We offer 3 video quality settings to help you manage your data usage. No matter what level you choose, your Netflix membership price will remain the same."
Thanks to JackH for sending this in.