Okay, I read this thread and immediately pounced. I was gonna send the rebate in 2 days since I've been so busy. I bought my macbook pro and ipod and printer on june 28th. Today is july 31st.
After talking to apple on the phone for about 30 minutes, and being on hold for about 25, I finally got to talk to a CSR from the rebate center (they had a hard time reaching them).
Basically, you have a 15 day grace period from that 30 day thing. So, in effect, you have 45 days from date of purchase.
My excuse was "the guy at the store told me to wait 30 days before sending it in just incase I needed to return it." she said "dont worry everyone gets a 30 day grace period"
hope this helps guys