I've heard (and, in fact, I think it came from Looch, but I could be wrong) that you can print tickets at StubHub's Last Minute Services. It's about a 5-10 minute walk from the Garden.
I don't know if that means that you can go in there, give them a credit card, and they'll simultaneously buy and print a ticket for you, or if you can go in there with a previously bought ticket and ask them to print it. I also have no idea if there are big crowds and/or a line there during game nights. I've only been there once, but that was just to pick up a physical ticket for Rod Stewart.
I do know that they definitely won't scan .pdfs - like Looch said, just the square codes that you can put on Passbook on your iPhone. It's their way of making StubHub less convenient, and hence TicketMaster/TicketExchange more convenient. You can't tell me that, all of the sudden in the middle of the year, it became "difficult" because of the "low quality phone screens" to scan the tickets. It's a money grab.
They were so strict with the new policy that, in March, I got turned away by one guy even though I had a QR code on my phone. Fortunately, someone else knew that it was allowed.
Looks like I'm stayin' home tonight....1200 tickets now, $270 to get in. For those who don't believe in jinxes, any feelings on Saturday? If Game 2 of the Canadiens (also an early series Saturday early bird special) is any indication, it feels overpriced.