I use Twitter favourites almost exclusively to mark posts that I know will be useful in some not-too-distant future; kind of like a Twitter Evernote. Recently I was looking through my list in search of this excellent blog post detailing how to build cross-platform binary distributions for conda.
I came across two other tweets from the EuroSciPy 2014 conference: this one by Ian Ozsvald about his IPython memory usage profiler, right next to this one by Alexandre Chabot about Aaron O'Leary's notedown. I'd forgotten that this was how I came across these two tools, but since then I have contributed code to both (1, 2). I'd met Ian at EuroSciPy 2013, but I've never met Aaron, yet nevertheless there is my code in the latest version of his notedown library.
How remarkable the open-source Python community has become. Talks from Python conferences are posted to YouTube, usually as the conference is happening. (Add to that plenty of live tweeting.) Thus, even when I can't attend the conferences, I can keep up with the latest open source libraries, from the other side of the world. And then I can grab the source code on GitHub, fiddle with it to my heart's content, and submit a pull request to the author with my changes. After a short while, code that I wrote for my own utility is available for anyone else to use through PyPI or conda.
My point is: join us! Make your code open source, and conversely, when you need some functionality, don't reinvent the wheel. See if there's a library that almost meets your needs, and contribute!