If your local lab doesn't offer the types of output you want, you can order prints online. There are several options, from traditional photo labs that offer web-based orders to photofinishers that are exclusively on the Internet.
Many of the top professional labs around the country will accept digital files through FTP upload. They'll print your images and ship them to you. If you choose this route, requesting test prints is a must, at least until you establish a relationship with the lab and are confident that the results will meet your expectations.
You might be able to access photofinishing services from within your imaging software. For example, Mac users can order prints up to poster size (depending on your file's resolution) simply by clicking the Order Prints button in Apple's iPhoto software. These services are terrific for reprints that you wish to send to family or friends, as you can have the prints shipped directly to them.