PHPMaster.com has posted a tutorial showing you how to use the cURL functionality that can be built into PHP. Note that not all PHP installations will have this extension installed, but most will these days. You can find out by making a phpinfo page.

If you’re a Linux user then you’ve probably used cURL. It’s a powerful tool used from posting mails to downloading the latest My Little Pony subtitles. In this article I’ll explain how to use the cURL extension in PHP. The extension offers us the functionality as the console utility in the comfortable world of PHP. I’ll discuss sending GET and POST requests, handling login cookies, and FTP functionality.

He walks thorough the basic flow of a request and how to set options on the cURL handle to modify its behavior. Several more "real world" examples are also included:

• Retrieve a Web Page
• Log in to a Website (via POST data, not HTTP Auth)
• Working with FTP
• Sending Multiple Requests

That last one changes things up a bit and uses the curl_multi_init function to create the connection and allow for the multiple request streams to happen.