This one is interesting, but because it was pending while I was clerking, I don't want to see a lot about it. Basically, the patentee was faced with deciding whether to pay the 7.5 year maintenance fee, and decided not to because there was no commercial interest in the patent. Two weeks after the lapse, someone expressed interest in it, and the patentee filed a form that said the lapse was unintentional. The district court found inequitable conduct on summary judgment; the panel reversed, with Judge Clevenger dissenting. The case, authored by Judge Newman with Judge Wallach, Network Signatures v. State Farm, is here.