Creating and using a test certificate with a WCF service
Since I've just lost a couple of hours trying to configure my WCF service to use SSL, I've though I'd put the steps here for self-reference.
The first thing you need to do is to create a test certificate. Since I'm running Vista+IIS 7 (workstation), I've used makecert with something like this:
makecert -sr LocalMachine -ss My -a sha1 -n "CN=url-you're-using" -sky exchange -pe
Basically, the previous command creates a new certificate and puts it in the Personal folder of the local machine store. It also configures the private key so that it needs to be exported.
After doing this, it will be necessary to export the certificate and all the certificates in the certification path - normally, one: Root Agency. Then you'll have to install them in the clients that want to use the client (normally, the root agency certificate will be installed in the trusted publishers and the test certificate should be put in the trusted people store of the local machine).
After performing these steps, you might still need to give access permissions to the private key to the service running the process that hosts the WCF service (WCF sampls have a tool called FindPrivateKey that helps you in finding the file that has the private key of the service).