The technical glitch du jour (and there always is one) is with adapters for the Mac to hook them up to an LCD projector. Old Macs apparently have different connections than newer Macs, and there are at least three kinds of adapters involved. We've been able to triage by lending Chris' Mac to a couple of presenters with adapter problems, but even Chris had been worried at the beginning of the day that he'd forgotten an adapter.
It's always too bad when A/V glitches happen. Speakers put so much work into their presentations, it's a bummer when something like a missing adapter trips them up.