If you're using git-osx-installer to install Git on Mac OS X Lion, and 'git --version' in Terminal isn't displaying the version you've just installed, then your system is using the version of Git that's provided by Xcode Developer Tools.
To use the git-osx-installer version that you've just installed, you'll need to edit the /etc/paths file and add "/usr/local/git/bin" to the top of that file.
To open the file for editing, type
sudo nano /etc/paths in Terminal. Add the "/usr/local/git/bin" line to the top of the file. To write the file, and exit nano after making that change, type
Control-X. To allow the change to take place, you'll need to quit Terminal, then open it back up again.
git --version should now report the newly installed git-osx-installer version of Git.
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