It really just makes sharing webpages and files totally seamless, but it's not as disruptive as texting, as noisy as facebook or twitter, and it doesn't flood your email inbox. Also, I know exactly who is getting what, it all lives in my Dropbox account, and the file format is totally transparent so I am able to do whatever I want with my data.
I am excited to take a look at the code. A friend and I were actually already working on a simple mobile app because we use this so often--now with access to the code things should go a lot faster.