Whats the best method of whitening the oh so common yellowing system?

[jeremysart]

From Commodore 64 to Atari 400, Coleco Adam to IBM 5150, from Intellivision II to SNES.. many of these good old systems have one large thing in common:

Yellowing (like teeth after too much coffee )

 

So does anyone have any suggestions or methods for restoring these beasts former beauty that you can share with the community?

[+RevEng]

Pinned in the A8 forum... http://www.atariage.com/forums/topic/138244-how-to-remove-yellowing-from-an-old-atari-case/