I don't know if anyone else has this problem, but I always struggle to find gifts for family members around Christmas time. I don't have time to construct anything tacky and handmade, and my parents and grandparents are well-off, so there doesn't tend to be an item that they covet that I can actually afford to give them.
So instead, I tend to do honorary donations in their names through programs like World Vision, DonorsChoose, GlobalGiving, etc. It's fun; for example, say your granddad is passionate about robotics. Then you go to DonorsChoose, find a teacher in an impoverished area who wants to teach kids math and programming via robotics, and donate in your granddad's honor. If you donate over $100 to the class, your granddad will be sent handmade cards from the entire class, plus updates throughout the year :) I've been doing this for a while, so I've been trying to get more creative. And one idea for bibliophiles is the Internet Archive.
In case you hadn't heard, Internet Archive had a fire last month. Fortunately, none of the archive itself was lost, but over a half a million dollars of equipment was destroyed. (although as far as I can tell, they're not doing a good job with backups, something they should definitely work on.)
The Internet Archive is a bit like Wikipedia: you use it, or services built on it, all the time, often without realizing it. Internet Archive powers the archiving of the web (including wikipedia links, actually), as well as the the digitization of books, texts, and videos.
Anyway, right now, due to an anonymous donor, they have a three-to-one donation going: if you donate $1, they receive $4.
It doesn't look like IA has a formalized "donate-in-honor-of" thing going, but you can still print out a nice card and, this holiday, you can give the warm fuzzy feeling of archival joy.