Web Design Question - How To Do This Overlay Effect on Mouseover?

[radderfire]

Hi All

Can you take a look at this page and tell me what is the best way to do the nice black transparent overlay effect when you mouse over the product images in the middle of the page.

Thanks

 

[radderfire]

Thank you for that.

 

[radderfire]

Can anyone give me a link for a good tutorial on how to create this particular CSS3 transformation, i.e. a transparent black overlay on any photo?

Thanks