I just spent hours in iPhoto making a slide show for my daughters wedding. I have not yet saved my work because was still tweaking and all of a sudden got colored spinning wheel. Is there a way I can save my slideshow before restarting computer to try and get rid of spinning wheel.
You could try leaving it for a while and see if it recovers on its own, but it probably will not. Unfortunately if an application is in that state, there's usually nothing that can be done. I don't know if iPhoto has auto-saving but I don't think it does.
You don't need to restart your computer to fix it, though. Click on the Apple menu then select Force Quit. Click on iPhoto and click Force Quit. You can then restart iPhoto and see if any of your work reappears.