Well, I must be the first person who cares to respond to you.. I had no problem in receiving my GC via the post. I didn't have to go to the office, it came to me via the mail and I got my card in 2008. I have also heard of others who applied around the same time as mine and have received theirs the same way. I'm in NY by the way. Sorry Bentlebee but back to school for you.
FABB, My GC was delivered approx 2 weeks after my interview at Port of entry. Additionally, you you become anxious during the wait you could also give them a call. My port of entry was JFK.