Desktop icons have become invisable

[ashbash]

I recently had what I incorrectly perceived to be a problem with my Mac booting up.
In fact the screen had been turned right down and I was seeing nothing! Yep sounds silly...
Anyhow in the process of of repeatedly rebooting 2-3 times until I figured out what was happening I have some how made all my desk top icons vanish from the desktop!!!!

Now they still exist. I can still find them via the Finder on the desktop but...I can not make them visable on the desktop...never had such a clean desktop!!
Can anybody help??

Cheers Ash