Hi Joe,
I think the first thing you've got to ask yourself is who are you writing the build log for?
If it's for the FAA (or CASA in our case) they really don't have massive expectations, and a simple log book with hours and a brief description will suffice.
If it's for helping others as you move through the process, then a web log is a great solution.
If it's for you and a document that you can have accompany your aircraft for the rest of its life (as it should) then as Mark says don't overlook the humble word document (or its Apple equivalent).
Although it may not appear as flashy, the upside to a word document is that:
1- It's easy to fill out. I would literally spend 2 minutes at breakfast hacking out some lines summarizing my previous days work, not for the FAA, but for me, so that if I have to go back and look at something in the future I will understand what I did so I don't make the mistake twice. I can not understate the importance of this, as you will work on things, botch them up, order new parts and a month later be back on that task again. Each day is simply a new paragraph with a date and a number of work hours followed by your comment. If it isn't easy, when you get halfway through and things get tough or time gets short, you won't do it, unless your the type that's really into recording things.
2- It's in a perpetual format. MS Word has been around since 1983 and I suspect it will be around for a long time to come. I bet there are still Mac programs that can read Clarisworks documents. There are plenty of hosting sites that have come and gone.
3- It's easy to word search, because it's all in the one document. This becomes critical over a long build when you want to go back and refresh your memory regarding what you did to a particular component.
4- It's small. My 100,000 word build log is only 339kB. I have plenty of photos which are in a corresponding folder. They can be sorted by date and easily matched up to my log entries. This makes is easy to load, save, send etc. because you haven't clogged it up with lots of formatting and pictures.
Frankly I started out with a word document because I was like you and hadn't decided yet on a fancy format to host my log, but once I got into it and I realized that I didn't want my log on full public display and that I was writing it to help myself and not primarily everyone else, I continued on with the word document. That's not to say that you can't help others with it. I regularly go back to this document and pull out relevant sections when posting solutions on this forum of sending them to other people, it's just not everything is out in the open the whole time. This encourages you to be more open about the analysis of your work as you move through the build, which can only be beneficial to the quality of your end product. It's fast, it's free, it's simple and it works.
Anyway, there's my 02c. A simple solution to a seemingly complex problem.
Tom.
RV-7