It really is fun to flick through diaries of previous years, and go down memory lane: "Remember that's when we first flew our xxx kites? And xxx then brought his xxx to play with. Gosh, the weather was an awful lot nicer than this year ..."
Besides the kite diaries, I also maintain a database of all the kites we've ever flown. For this, I use the same software I use for cataloguing my CD collection: Music Collector. With a few imaginative tweaks, it works pretty well for kites as well. Each kite we've ever flown, whether it's one of our own or one which belongs to someone else, has its own entry, and I always try to make sure I have a photo of it 'ready-to-launch' and one of it flying. Information in the entry includes when we first flew the kite, how often we've flown it, where we've flown it, plus information on size, wind range, price, lines used, bag it lives in, etc. Here's the entry for one of our Airdynamics Taipan SUL kites:
So yes, guilty as charged: typical male keeping lists. But Irma now (grudgingly) admits it is indeed fun, despite her initial scepticism!