A scrapbook is a good idea, so is taking all of their old photos and scanning them onto a CD, maybe cleaning them up digitally. If you make a scrapbook, make sure to treat the photos with care..maybe give them a dose of archival mist to neutralize the acid. If you don't want to go to the trouble, or are too cheap, the ubiquitous lavender bath set for grandma, the new weird tie for gramps.