If circumstances beyond your control leave you less than fully prepared for an interview, it's considerate to let your interviewee know. One radio talk show host did that today, telling his guest, "We're having a technical meltdown. The email's down, (and) the software doesn't work, but I know we're going to be talking about...immigration..."
I didn't hear the full interview, but I know it got off to a good--and honest--start, at least.
