Install Screen on RHEL 5.5

1. Download RPM from
  http://www.rpmfind.net/linux/rpm2html/search.php?query=screen
2. wget ftp://195.220.108.108/linux/centos/5.8/os/x86_64/CentOS/screen-4.0.3-4.el5.x86_64.rpm
3. rpm -ivh screen-4.0.3-4.el5.x86_64.rpm

Screen Tutorial

Upgrade to Python 2.5.6 on RHEL 5.5

Here are upgrade instructions for Python 2.4 to Python 2.5.6:
1. http://www.python.org/ftp/python/2.5.6/Python-2.5.6.tgz
2. tar xzf Python-2.5.6.tgz
3. cd Python-2.5
4. ./configure
5. $ make
6. sudo make altinstall
7. sudo mv /usr/bin/python /usr/bin/python_old_2.4
8. sudo ln -s  /usr/local/bin/python2.5 /usr/bin/python

Validate:
# python -V
Python 2.5.6