I use git for most of my writing (blog posts, content for my company's website, notes from meetings, journal entries about my kids, etc.) as well as for source code. Sort of a light-weight dropbox, with version control.

I've sometimes wondered (and perhaps this already exists, I've just never googled it) whether it would be useful to have a type of legal document that uses a markup suitable for revision tracking and version control. I find it's hard to be completely sure before signing a long legal document whether the version I've just received is precisely the same as the one my lawyer has reviewed.

It does not fulfill your needs exactly, but it may be a start: http://www.gnu.org/software/wdiff/

I seem to remember a tutorial on setting that up with git, but Google is failing me right now; does anyone know where that might be?

Um, git diff --color-words?

MS Word has a diffing feature. I'm not sure how to trigger it from the UI, but my current source control system activates it when you diff two versions of the same Word doc.

git/GitHub plus DropBox is like chocolate plus peanut butter

I hate peanut butter, does that make the analogy wrong?

I used git for keeping track of changes to my thesis. Since LaTeX is really just code, keeping track of the changes was pretty easy.

The slightly more novel thing was using it to keep my research articles synced. Lesson learned: downloading 30 or 40 journal articles in pdf form through git on a wireless connection can be very slow.

I actually keep my homework on github. :) And yes, depending on your pipe, downloading all the binaries can be slow. But the ability to have history and synchronization between machines (I probably use 4 or 5 computers on a regular basis) is super nice.