I think its been misplaced and I don't know what it looks like (in terms of the difference between it and the master key...please help!!! Thanks guys!

 

They look exactly the same...just check to see if it opens your glove compartment...if it doesn't...then it's the valet key.

 

For 04's the Valet Key was the one without the silver/chrome accents on the key (The infiniti symbol and section right around the ring hole) . It was the fully black key. So much has changed in the 05s I'm not sure what they do anymore

 

Same for the 2005.

 

05 is the exact same thing