Much will depend on who you buy it from - a typical mail order place wants to get it out the door same day and they often have their courier call late afternoon. If the order is placed in time for the packing person to wrap it up and fix an adress label it will probably go same day for an order placed before say, 15:00.
Shipping is another matter. Most courier companies take pick-ups to a central point for onward shipping the next day - depending on where you live and where the item is shipped from it may need several overnight stops along the way.
This all supposes of course that your chosen supplier actually has the item in stock - they don't always tell the truth about this or about the lead time they themselves expect from the stockholder they buy from - it was ever thus I'm afraid.
It is often good policy to go to the place where the part is and pick it up yourself if you're able to - this way you're in control.
This site is not a shop - just a free advice board.
Peccavi, July 2009