Question: Are there any half-official repositories for CentOS 5 with Python 2.7?

EPEL provides only Python 2.6

Answer: 
You can try my build adapted from Fedora 16:
<http://ftp.srce.hr/redhat/test/el5/x86_64/>
Not that I am aware of at this time, but then again it would be prudent to learn a standard gunzip make install instead of relying on package managers.