Recommend a solution to backup files - home pc to external drive

I'm looking for recommendations on software to backup files from my pc to an external HD. I'm not looking to image the drive or anything like that. I just want something simple (and of course preferably free or cheap) that I can setup once and run from time to time to back up files from a home pc (so we're talking pics & videos from a digital camera, excel spreadsheets, etc) to an external drive. I'm running Win 7 on the pc (currently RC, moving to retail upgrade this month).

What do you use? What do you recommend?