You are probably wondering what a tool named Dipity allows you to do that could be remotely educational. Well, if you are interested in creating timelines with your students then Dipity is a tool you might want to try out. It is web-based and free (isn't everything I write about?) and takes advantage of the many benefits of Web 2.0 functionality, which means you can add images and video from around the web, embed and share your finished timeline and even geographically tag the different events or entries on your timeline. Timelines can be viewed in multiple ways including as a flipbook on a map and, of course, as a traditional timeline. Check out the timeline I have included on JFK to get an idea of the kind of thing you might be able to create. Timelines can have multiple authors as well.
TimeTube is a mashup from Dipity that allows you to type in a keyword and then have a timeline automatically generated that includes a variety of videos that match your specific keyword. I like the concept of this but since there isn't a clear way to filter out videos you can get a lot of oddball stuff included in your timeline. For instance, when I used the search term "JFK" I got news footage and historical video clips along with a clip of a comedian who was talking about JFK and a video of people dunking a basketball to a hip-hop soundtrack. I realize I could have tried to refine my search term but it would be nice if you could edit the timeline once it was created to weed out the videos that don't fit with your educational goals.