I'm trying to install some software as it might help with my mouse getting stuck in one of my two screens.

I am issuing the following command and getting the response below.

git clone git://anongit.freedesktop.org/git/xorg/driver/xf86-input-mouse

GNU Interactive Tools 4.3.20 (i686-pc-linux-gnu), 18:50:22 Sep 19 2007
GIT is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation; either version 2, or (at your option) any later version.
Copyright (C) 1993-1999 Free Software Foundation, Inc.
Written by Tudor Hulubei and Andrei Pitis, Bucharest, Romania

git: fatal error: `chdir' failed: permission denied.

I can go to the freedesktop.org website and see various files to do with xf86-input-mouse, but you can't seem to download them from the site, they just come up as web pages.

Anyone dealt with git before and know anything about this or other ways of getting the code?

Are you sure you are using 'git the version control system' and not 'git the gnu interactive tools'? Are you using debian, ubuntu or any derivative? If so:
sudo apt-get remove git
sudo apt-get install git-core

On ubuntu (and debian probably) "git the version control system package" is called 'git-core', not 'git'.

cheers,
lukost

Ah you're a fine man!

(It's Mandriva I'm running.)