DVD rentals by post
Usually when I go to a rental store I wander around for ages, trying to remember movies that I might like, but with the Amazon rental list, anytime I think of a movie I just add it to my list. The web interface lets me change the order of the DVDs at any time, and for less than ten quid I get four DVDs a month, two out at any time (as soon as I send one back, they send the next one on the list, unless the monthly limit has been reached). Plus you get a discount if you buy any DVD from Amazon.
If you'd like to check it out for yourself, just click on the banner: