I like watching what other people do with my code. It often gives me ideas about how to improve the API or what features to add. I can also get a feeling of what the user thinks of my code: if he uses it differently it's an indicator that he either doesn't agree with my design choices (whether they were conscious or not!) or he's struggling to understand some of the concepts, which I may have left implicit or undocumented. In a nutshell: a different perspective.
For code published on github, this is easy to do: just watch the forks. But I always seem to miss some fork, so here's a script that watches all forks in a github network:
You can get your github API token from https://github.com/settings/admin
Going further, I like doing these reviews from gitk. So here's another script that adds all repositories in a network as remotes:
I then run a "git fetch --all" and browse the commits in gitk.
Of course, this works on networks with relatively few forks or not a lot of activity. YMMV.