Oh gosh yes! I remember files (and endless filing!) and all the paraphernalia that we kept our records in pre-technical times! Carmi over at writteninc. has posted a pic of a lovely old reference book, complete with little tabs for finding things more easily. Usually, the tabs fell off!!
I can't do as good as that, but I did sort some data out.
My old files - bank statements, pay sheets, you name it, its there!
Birth Marriages and deaths are probably the most common data collected. But by my church, its all there, inscribed on stone!
And then there's the phone book, fill of information, though quite how you'd analyse it, I'm not sure.
Call in at the link above and see what other data you can collect - and post your pics, too.