You can find them at http://youtube.com/user/blogdiva [1]
They're not the bestest quality but you can get a good sense of the excellent presentations by the likes of Van Jones, Mark Pesce (who I've already written about), Brian Behlendorf, Craig Newmark and others.
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[7]Links:
[1] http://youtube.com/user/blogdiva
[2] http://del.icio.us/post?url=http://culturekitchen.com/liza/blog/my_pdf2008_video_clips_are_up_at_youtube&title=My+PDF2008+video+clips+are+up+at+YouTube
[3] http://digg.com/submit?phase=2&url=http://culturekitchen.com/liza/blog/my_pdf2008_video_clips_are_up_at_youtube
[4] http://reddit.com/submit?url=http://culturekitchen.com/liza/blog/my_pdf2008_video_clips_are_up_at_youtube&title=My+PDF2008+video+clips+are+up+at+YouTube
[5] http://ma.gnolia.com/bookmarklet/add?url=http://culturekitchen.com/liza/blog/my_pdf2008_video_clips_are_up_at_youtube&title=My+PDF2008+video+clips+are+up+at+YouTube
[6] http://www.newsvine.com/_tools/seed&save?u=http://culturekitchen.com/liza/blog/my_pdf2008_video_clips_are_up_at_youtube&h=My+PDF2008+video+clips+are+up+at+YouTube
[7] http://technorati.com/cosmos/search.html?url=http://culturekitchen.com/liza/blog/my_pdf2008_video_clips_are_up_at_youtube