Once you start looking, you'll "notice" that they're everywhere: Myriad signs with odd and unnecessary quotation marks. For instance, one that tells you there "will" be an extra charge, or another that urges you to step right “in”.
The Blog of Unnecessary Quotation Marks photographically chronicles these oddities. Just click the highlighted link and “scroll” down to see some amusing examples.
Ernster, the Virtual Library Cat