Apparently the Canon point-and-shoot we own, the PowerShot SD110, has a known issue with the CCD going bad and distorting images. According to the service notice, they will replace the CCD, but I don’t know if this offer is still good. I’m going to call tomorrow to find out.
Update: They believe the problem is theirs to fix (but aren’t sure yet). They have sent me a prepaid UPS label and an address to their repair facility so that I can send it in. For a four-year-old camera clearly out of warranty, I am truly impressed by their customer service. This is the kind of thing that keeps me loyal to the brand.