If you've ever wondered how much you're costing Netflix when you go on those month-long movie binges, you should give Feedflix a go. It takes any one of your personal Netflix RSS feeds and figures out how many movies you're watching per month and what the cost comes out to for each DVD. It also breaks down your biggest return days and how long you tend to keep titles.
Ultimately, most of this information is useless, as with some simple math a Netflix membership tends to end up costing less per-rental after just four DVDs based on the most popular plan. Where you get the value is by coming back a few months later since it keep tabs on your RSS feed over time. You'll then have a better analysis of your watching habits and know if you if you need to get out of the house more often, or if it's time to ditch Netflix altogether.
What makes the service truly interesting is its graphs of other Feedflix users. It will group together this information and anonymize it, giving you a bit of a peek into other people's habits. There are charts of the average rental period, popular plans, and most frequent return days. However, the neatest one of the bunch is the breakdown of other users' queue sizes. According to Feedflix, about a quarter or more of users have queues in the low hundreds which is truly impressive. I'd be very interested to see how this data stacks up with subscriber information from the source.
Feedflix is completely free of charge, however you will need to be a Netflix subscriber (or friends with one) to make use of its data crunching prowess.