Video Time Machine, free this weekend on the App Store for both iPhone and iPad, is one of the most entertaining apps I’ve played with in a while. Like all good video viewing apps, it’s based around one simple curatorial concept. In the case of VTM that concept is — yep, you guessed it — time. Dial up a year and the app pulls from YouTube videos produced during that year. You can further drill down by category, browsing TV, movies, music, sports, news and advertisements. And, there’s a curatorial element: the videos are “hand-picked” and always seem to strike a nostalgic sweet spot. The app is tremendously fun to play with, but it’s also of use to writers, directors, art departments and other researchers looking for quick visual reference points for their scripts and films. And, of course, you can tweet and Facebook your results.

Check out their commercial.

The app also has a Tumblr blog and a couple of sister apps, including Political Time Machine, which finds moments from throughout candidates’ careers. Opposition researchers take note of this one.

Here’s a find of mine from playing around with the app: a commercial for the NBC series Then Came Bronson, from 1969 — a time when network television and The Brown Bunny were not so far apart.