If you don't want to clone all #git repo, for example:

git clone git://github.com/rubinius/rubinius.git
Cloning into 'rubinius'...
remote: Counting objects: 226027, done.
remote: Compressing objects: 100% (55389/55389), done.
Receiving objects:  35% (79200/226027), 20.39 MiB | 32 KiB/s 

You can specify depth level:

git clone --depth 1 git://github.com/rubinius/rubinius.git
Cloning into 'rubinius'...
remote: Counting objects: 54128, done.
remote: Compressing objects: 100% (29197/29197), done.
Receiving objects:  28% (15167/54128), 6.91 MiB | 67 KiB/s 

For this case it's 226027 vs 54128 objects or 60 vs 30 mb.

https://git.wiki.kernel.org/index.php/GitFaq