Hi all,
1. Logo graphic and favicon.
2. Shorter URLs.
3. Tweet button.
4. Open Graph metadata.
That last point means that if you post a link to a point on Facebook, it will show the point text in the summary that appears on the feed.
I had a look at including a Facebook Like button, but urgh... so evil. Do not want. The way Twitter's button works is much less evil, privacy-wise.
- Ben.