How to fade right side of image to black?

[jpcush]

Hi, I have several 750x250 jpeg images which I am using for a website. I need to fade about 20-30 pixels worth on the right side of the images to black.
How can I do this? What software do I need? Is there any 'free' software which will do this for me?

This is my first time on this site so forgive me if I have posted this at the wrong location.

Thanks

Harry

[burgkamp]

I would use photoshop to do this. If you don't have the software I'm more than willing to do this for you. Let me know )

[rockon]

Make a gradient in the Alphachannel in PS?
I think...?