Communicating electronically, be it via email, Twitter or anything else, is never quite as good as meeting people in person. Rapportive shows your contacts' happy smiling faces in your email, which helps a bit... but still, wouldn't it be better to just meet face-to-face?
Lanyrd's social conference directory also allows you to keep track of conferences in the past, and if any of your contacts have been speakers, you can check out their slide decks and videos.
How do you add this to Rapportive? Why, same as all Raplets — click the Rapportive menu at the top of Gmail, then "Add or Remove Raplets". Enjoy!