Yesterday I was trying to compile something that required gcc. To my horror gcc was not installed on my Snow Leopard.
Strange, because it is said that gcc comes as part of the developer tools.
Apparently not. I needed to install the developer tools from the Snow Leopard CD itself. Which worked.
Which caused a problem of me losing my entire SDK for iOS. Which needed to be installed once again. (2.9 gig download - ouch)
This nice blog has a link to all the different XCode downloads for iPhone/iPad SDK, etc: http://chris-fletcher.com/2010/08/28/howto-install-iphone-sdk-2-0-3-1-for-xcode-3-2/