@bb052609 Do you have AppleCare+ or is it out of warranty?

Depending on the capabilities of the Apple Store you bring it to, many repairs can be completed the same day. It'll depend on what's wrong, which model you have and how well-stocked with service parts and well-staffed with trained service people they are.

They will tell you at the time of your appointment whether they can fix it in house or need to send it out.

Apple *does* have a loan program for long-term service situations. 

 @bb052609 also, strongly recommend sticking to Apple for this, not Best Buy or anyone else, even if they're Apple-certified. 

 @03a95182 Thanks! This is helpful.

And I just found the date I bought it. Miracle of miracles, the phone is still under warranty for six days!