In the next of her series looking at OAuth in PHP, Lorna Mitchell has posted a look at request tokens and how to hand them out via your application.
The consumer requests a request token (see my earlier post about consuming OAuth), and as a provider, we need to handle that request. In my example, I chose to pass the variables as GET parameters, but you could adapt this to handle POST variables or information contained in HTTP headers.
She includes the code (using the functionality of the pecl_oauth extension) to provide a token and the three functions you'll need to define to get things working - the consumerHandler, the tokenHandler and timestampNonceHandler. She also includes a sample database table structure for storing the OAuth information for a user.