Thanks to rodjek and technoweenie the trailing “.git” is now optional when cloning GitHub repos using SmartHTTP:

$ git clone http://github.com/tpw/endo
Cloning into endo...
remote: Counting objects: 6, done.
remote: Compressing objects: 100% (3/3), done.
remote: Total 6 (delta 0), reused 6 (delta 0)
Unpacking objects: 100% (6/6), done.