Everybody knows about
permalink, but it's usually used only in
get_absolute_url. I prefer to use it for all related model urls.
And then in template:
In my current project I had a task to use twitter API. Twitter uses OAuth for authentication, which is pretty dreary. To avoid fiddling with it all the time, I've moved authentication to decorator. If key is available - nothing happens, just view is launched as usual. It's convenient that there's no need for additional twitter settings in user profile. Code is in article.