Nike Running Club will be raffling off entries for the Nike Run the Rock event taking place on Saturday, September 15th @ 10:00 a.m. If you were not able to register (evidently it sold out the morning of September 7th), this is your second chance to get an entry.
Just show up at Niketown Running Club (RUNNYC) on Tuesday, September 11th (6:30 p.m. @ Niketown - 57th & 5th) and Wednesday, September 12th (7:00 p.m @ Runners Station - 16th Street & West Side Hwy). They'll be raffling off entries to those that try on Nike shoes during their run.
Also, I've heard from some RUNNYC members that they signed up and don't plan on participating. Some signed up for the free t-shirt and others have to work or have plans. You might want to befriend those peeps as they might "give away" their entry. But can't be sure until Saturday if they require participants to wear the t-shirt so you might want to ask the RUNNYC coordinators.