Hi Michael & All,
Nope, no trade secret. I keep my log within a piece of astro-database software called Deep Sky --
http://www.deepsky2000.net/
I've been using it for about seven years (mind you it was quite a bit dearer back then). Before that, my log was all hard-copy manual (it took a long time to type it in and scan where appropriate). The software is a (huge) astro database also from which I make most of my "to-do" lists.
It works reasonably well but I am considering (not yet certain) changing over to another system. The new version of Skytools is a lot less ummm ... "clunky" and there are others.
My log is fairly "sizable" and obviously very, very valuable to me. The 'scope and the eyepieces etc are much more replaceable than the log ! It is backed up in two other places at home, and a copy at a friends home.
Best,
Les D