I originally started using Flight Log so that I could come up with an idea of how much RC "stuff" I had for insurance purposes. It's good that I did because originally I was only covered up to $10,000 in loss on my RC stuff, but when I found that I had closer to $20,000 worth I changed my policy to cover it all. Since then I found I just like keeping track of it all.

I have a little card that I printed out that I keep in my transmitter case. I record date, temp, wind, each flight, which plane, minutes flown, and fuel used. I transfer it to my PC when I get home at the end of a day (or actually at the end of the weekend)

I've been working with Shawn (the author of flight log) and currently in beta testing on the next version of flight log which allows a picture for each item. I really like the new version, but I don't know when it will be release so keep an eye out for it.