To obtain this global connection for conferences you need to use 2 webbased tools. First the use of a Twitter hashtag to tweet and reach other people outside of your conference walls is so easy to create. Just make sure that your hashtag wasn't already taken for something else. Then just start using it. Try tweeting out with that hashtag with other hashtags in your comment so it gets threaded to others. And I would recommend tweeting about the hashtag before the event to start dropping the conference event in others' heads.
To bump up the tweeting aspect, get others attending the conference to tweet. Have them post what they are hearing and seeing, share links, and upload photos. When a hashtag is being used a lot in a day people will notice and start following!
A second aspect of connecting your conference globally is through another free tool called uStream (which is the one I have used, but am well aware that there are other sites that do this same thing.) To set up this you really need a pretty decent microphone so that people at home are not frustrated with the audio, a web camera, and the internet. Once you have the URLs established through uStream, have someone monitor it during the conference to make sure that the virtual audience is being heard. (There is nothing more frustrating than watching a conference virtually and not be heard than represented IRW.) If you click the little record button you would even be able to archive the presentations to share with others whenever they feel like watching!
Here comes my plea to administrators and board members:
With so much online professional development going on via Twitter, Nings, Blogs, etc I am growing professionally every day versus the painful cut out inservice days before the start of school. Now don't get me wrong, I actually liked inservice (once I finally got there and knew I had to sit through the day) and always came away with some useful tip but that "forced to grow on this day" is just a thing of the past. More schools are counting attending online webinars towards PD and I say, "Hats off!" I would like for us global professional developers to start some simple spreadsheet and log what we attend, read, participated, etc. Even if your record is something like "twitter - used through out day and got 3 ideas, or 2 links to use in class" "followed #conference tweets" "watched archived webinar on this topic" "read Mr. Joe's blog post" I bet that your admin team would be floored how much more your are growing now than you ever had in your years on the job. And I think that teachers participation via online education communities should be recognized and rewarded for effort.