You can also install Git on your own Linux system. Git is available for installation as a package within most Linux distributions and can be installed that way (e.g. using yum on Red Hat systems or apt-get on Debian systems, or their graphical interfaces). You can also install from source code.
If you use Windows and have Cygwin installed then you can install Git as a Cygwin package. A version of Git can also be obtained from the msysgit web site.
If you use a Macintosh and have Fink installed then you can install Git as a Fink package. A pre-built binary is also available at Google Code