I realize I'm not cutting edge here or anything, but I just participated in my first "webinar," on eminent domain reform. (platform: Elluminate) It worked quite a bit better than I expected, rather nicer than the interface for the one e-class I took. Submitting questions to a queue via chat, and being able to post your own answers individually to others while the presenters were talking was nice.

In terms of ease of joining a group and being able to hear everyone, it was soooooo much nicer than a conference call, and especially nicer than trying to sit in on a real-space meeting by speaker phone (which is only slightly this side of utterly pointless). I guess it would have been awkward for a real back-and-forth conversation, but it's something I would do again.