Mac – Xcode appears to be installed but xcodebuild is unusable

I was had to reinstall Xcode 4 and now I'm getting message Xcode appears to be installed but xcodebuild is unusable; and xcodebuild exists but failed to execute all the time when I try to install anything using ports:

ash-3.2$ sudo port install wget
Password:
Warning: xcodebuild exists but failed to execute
Warning: configured user/group adm does not exist, will build as root
Warning: Xcode appears to be installed but xcodebuild is unusable; some ports will likely fail to build.
Warning: You may need to run `sudo xcode-select -switch /Applications/Xcode.app`
--->  Computing dependencies for wget

xcodebuild exists but it wants to another one xcodebuild or it just wants to be in /Developer folder?

$ which xcodebuild
/usr/bin/xcodebuild

$ /usr/bin/xcodebuild 
error: can't exec '/Developer/usr/bin/xcodebuild' (No such file or directory)

What's wrong with this utility? How can I fix it (I've already reinstalled Xcode)?

Update:
port worked fine even without xcodebuild, I think MacPorts uses make and it showed this message just to make me know that I may have a problems with Xcode.

That's interesting. I've tried … xcode-select … but for some reason it newer worked even after reboot, but today it worked :|. It asked me if I want to accept the license agreement and after I accepted it xcodebuild become functional. So now I can accept answer and thank everybody.