Here's the backstory...
So I'm heading into London with a connecting train to catch and reading with abject horror about the total chaos the Tubestrike is causing (solidarity to the workers!).
I'm starting to panic about how the hell I'm going to get across town in time for my train when I see someone tweeting the hashtag #tweetbike and a twitpic of a fetching black motorbike.
To my delight I find Paul Clarke using Twitter and the #Tweetbike hashtag to co-ordinate lifts around London on his shiny motorbike.
One quick tweet and I've booked myself a ride. Fifteen minutes later and we're weaving in and out of gridlocked traffic and I'm on time for my train.
On the face of it, it's an awesome idea. This MacMillan Open Dictionary definition defines it perfectly.
But it also opens up loads of exciting possibilities. #Tweetbike is simple, pure and effective collaboration utilising widely available and easy to use mobile tools. But it also mixes online, virtual collaboration with real-world outcomes.
As Paul explained to the BBC last year, #Tweetbike is:
"an exercise in how fast and how little effort it takes to make something happen in this situation. It has also helped me get a deeper understanding of how social media can work. It's a sort of mashup with my bike and Twitter."
But let's not forget that at the heart of this project is social capital.
Paul told me as I got on that someone had just tweeted how #Tweetbike was a murder waiting to happen which he found odd. What this perspective misses is that #Tweetbike isn't a pirely transactional service - it is driven by a deep social trust that Paul has built up through his personal network - both online and in the real-world.
And it's this element that is key to the success of this - and potentially similar projects. The one drawback is that this kind of trust is difficult to scale in a mass marketised world.
But that's a good thing because hopefully it will lead to more specialised, socially powerful, rewarding initiatives like this one.