How do I reboot my iMac without a keyboard?

Hi everyone,

My iMac keeps getting stuck on the start-up screen (grey with the rotating circle thing) and never reaches the login screen. I have tried all of the hold down the "command" key, put in Mac OS X disc and hold the "c" key down, hold down the "shift" key etc. troubleshooting recommendations I can find online but... My keyboard hasn't been functioning properly either. I think it's a computer issue and not a keyboard issue because the keyboard is getting power (when I hit the caplocks key it lights up).

So onto my question: does anyone know how to reboot an iMac without using a keyboard?

Thanks a million in advance for anyone with suggestions. I have been working on this for the last 6+ hours and am ready to pull my hair out.

(p.s. I brought the computer over with me from the US but now live in the Philippines. Because of my location I would rather not bring it into a Mac store as I don't really trust the service I might get there with Apple products)