I requested two keys on behalf of someone else using two different emails. I did the request on Friday, December 1st. My friend received the first email earlier today to his Yahoo address. He's still waiting on the one to arrive at his AOL address. So four days was the net time for the one anyway.
I noticed that keys arrived faster (sometimes immediately) at my various hotmail/live email addresses. Whereas an aol address took a week. If you enter the same email address that you used previously, they will send you the same key. This may get one "re-sent" quicker (if it has been a few days) even if they haven't sent it for the first time yet. That is my theory anyway, based on experience. I also usually refresh my IP and dump out the stalking stuff stored by the browser before requesting another one.
An easy way to get more than one key per-email, is to type this "*emailaddress*+1@gmail.com" ***EDIT, SORRY DIDNT REALIZE IT WAS ONLY GMAIL!***
you can get multiple keys using a gmail account. For example you have user123@ gmail.com, you can also enter u.ser123 @gmail.com, us.er123@ gmail.com, use.r123@ gmail.com, so on and so forth.
got a new batch of keys in 84 hours - using safe-mail.net with myemail111 myemail222 myemail333 etc... use private browsing and clear everything before requesting for a new key