Merriam-Webster announced more than 100 additions to their Collegiate Dictionary yesterday. In a press release that is heavy on the fun of misheard song lyrics (a "mondegreen"), the president and publisher makes special mention of "webinar" - "One more example of the significant ongoing trend for electronic technologies to add words to the language."
So the next time someone complains about this non-word, I'll just direct them to http://www.merriam-webster.com/dictionary/webinar...
Webinar: a live online educational presentation during which participating viewers can submit questions and comments.
(I'll leave aside the fact that I have sat through some webinars that weren't very educational!)