On that last issue, as a lawyer, I've sometimes attended continuing legal education seminars that are nationally webcast. As for the social interaction aspect, various law schools around the country "host" (in the social sense, not the techie sense) the webcast as if they were actually hosting the seminar. So how about this: a national conference is webcast to local genealogical societies?! Seems like a potential win-win for all.
Last spring, I was quite excited by the possibility of attending the Conference in the States & Family History Fair of the National Genealogical Society. I'm a member of NGS. The Conference last year was held in Richmond, Virginia. The venue afforded opportunities to mark the 400th anniversary of the first colony in Virginia as well as the 225th anniversary of the Battle of Yorktown (which was the previous October).
The sessions and speakers at the NGS conference seemed very interesting and struck me as the most exciting conference lineup I had ever seen. But alas, I had already planned the Big Train Trip to Missouri, so time and finances conspired to keep me away from Richmond.
My perception has been that a lot of the big conferences are held on either Coast or in major cities. I understand the practical reasons for that. But how about a really major conference in mid-America?
Imagine my thrill when I signed into the NGS page not long ago and discovered that next year's NGS Conference in the States & Family History Fair will be in Kansas City!
I've just been to Kansas City on my research trip this year, but I'm ready to go back next spring! Kansas City is a very affordable city and there's a lot happening there. I can't wait!

The clever parking garage across from the Kansas City (Mo.) Public Library