How can I effectively hide my macbook while traveling to prevent theft
Searching on the web for "laptop skin" or "removable laptop skin" would provide you a list of designers and sellers for laptop skins. Buy a boring laptop skin and use it on your MacBook Pro.

Some sites for laptop skins (in no particular order):  


CafePress  
Gelaskins  
Zazzle  
DecalGirl  
Skinit