1.Create an Official Hashtag for the event well in advance.
2.Display Hashatags strategically at different place at the event, in communication materials like brochure, also on event backdrop banner. Keep the hash tags visible and prominently displayed.
3. Encourage participants to use Hashtags in tweets. May be you can pick up few question posed by the audience from the tweet feed.
4.Use this free web app for projecting live tweet on a screen http://www.twitterfall.com/ (Free)
5. Create an account with above mentioned apps, free or paid.
6.Create settings based on your need & requirement for the live tweet feed.
7.You can block /filter/moderate the tweets to weed out inappropriate & abusive tweets. You can also use filter for tweets by mentioning abusive words in the settings.
8.For this you need a dedicated laptop & social media savvy operator for the live tweet feed.
9.In case , an offending post makes it through your filters, a social media savvy moderator watching the feed can quickly remove off-topic or inappropriate posts from public display.
10. You are now good to go for an integrated Talk & Tweet Session.
**Good Internet Speed Is Must !
How it helps : It takes your message from a closed room session to the global audience! People interested in the topic can connect from anywhere.