Recently, I went to see Star Trek (yes it was awesome, all the things you've already heard). My problem was that this movie was pretty much non-stop - and with about 30 minutes left to go I had to urinate with a capital URI. I made a mad dash for the door at the end, and ultimately there was no violation of my personal Prime Directive (that is, Never Piss on One's Self in a Movie Theatre).
Still, it would have been great to know, going in, when there might be enough of a lull to hit the loo. Never fear, the folks at RunPee.com have our collective large-soda-drinking back. Search for a film, and you'll see when it's best to slip out for a self-proclaimed intermission. It even tells you how long a given pee-break will last, so you know if you've gotta rush it.
And just when you thought we couldn't make you're movie-going life any better, I humbly direct you to MovieStinger.com. This fancy-pants service lets you know whether a film has one of those plucky little post-credit barbs that everybody will be talking about tomorrow. Since you consulted RunPee, you don't have to do any mad bathroom dashing, so you can leisurely relax and enjoy an extra 90 or so seconds of movie goodness. (Note: The MovieStinger example image suggests you should stick around after the newest Night at the Museum movie. This implies that you were inclined, without encouragement, to sit through the rest of the film. Highly Recommended Thing of the Moment accepts no responsibility for any mental anguish endured during a Ben Stiller sequel.)
And in case you're a non-theater-going type, check out FeedFlix. This site links to your Netflix account to help you monitor whether your montly fee is, in fact, less that you'd fork over to your real-life flesh-and-blood movie rental shop. It even includes a service to let you know when a movie has just been available to stream.
There you have it, folks. Go forth and view film.