I for my job I have been using a service called Animoto. My work has a paid account. However, I have really enjoyed creating the videos using this program and created a video of some of my past and more recent work.
I did this with my very own free account. The free account has some limitations. You are limited on the formats you can use. You cannot do the sound editing and you are limited in time on many of the videos.
However, with that said I am still pretty happy with the results of this 30 sec video.