Comment from: http://code.google.com/p/git-osx-installer/wiki/OpenInGitGui

The AppleScript? in this one opens a scratch terminal. This can be avoided by using, instead of "tell Application Terminal do script [...] end tell", just this (without invoking the Terminal):

do shell script "(cd " & listOfAliases & "; /usr/local/git/bin/git-gui)"

I believe I tried that already, and still had the same issue.

I was finding I needed to open a terminal or else fetch / push wouldn't work over ssh, which was the whole motivation for writing the OpenInGitGui icon.

If you find otherwise, please let me know