I just discovered a great resource for backgrounds, video loops, etc., stuff that I haven't see used a lot, yet...
istockphoto.com, provides free weekly photos and videos for those who join, and you can tap into a pretty good archive of material, too. I'm teaching a series using gardening as a theme, and so I searched the video archive for gardening, and came up with several good jumpback type loops to use...

This may be old news to everyone else. I'm just beginning to emerge from the dark ages...