I know that the post title looks like a dummy tutorial, but actually it's more a bug report.
In the past I had no problem setting up the Google Analytics tracker for my Google code projects, but I tried it today and it's more complicate due to what like looks to be a bug.
The problem is when creating a new profile and specifying something like code.google.com/p/myproject as the URL to be tracked, because now, just domain names without any path are allowed, and n "Invalid input" error is raised.
The solution is simple if you know it. You can create your profile just with the domain name (code.google.com), and then edit the profile and update profile name and profile url to the correct values (in this page it's allowed).
I guess that it will be quickly solved by the Google team, but until then, here you have the tip.