This is a quick one. You can get free SSL certificates at https://www.startssl.com/. They don’t look good when inspecting the certificate itself (name, etc removed as this is not verified) but it looks good in the browser.
Go ahaed and give it a try. Free for multiple certificates. Also works fine for SNI enabled Apaches (of course) in case you only have one IP but require multiple SSL sites. I have used them a lot and I’m very happy with it.
You will need to be in control of the domain in order to get the certificate. For validation you will need to have access to one of the following email accounts:
After clicking the validation link, you can requet the certificate. This will need to be approved by an employee of start SSL but this happens almost instantly. I never had to wait more than 20 minutes.