git cloned test.html did not work with latest versions of Firefox, Chrome, Safari for me, yet yours does. I find it strange that there's some policy more restrictive on local content than on remote one, provided yours work perfectly.
Chrome does not allow scripts to access files on a local filesystem unless you specifically tell it to do so by starting it with --disable-web-security as an argument.
See http://code.google.com/p/chromium/issues/detail?id=40787 for a discussion (and a lot of frustrated people).
To simply start an arbitrary HTTP server to serve up files in a directory I use python's SimpleHTTPServer. This works on most Linux and Mac boxes as they package python along with the distribution or the OS.
python -m SimpleHTTPServer
This serves the files off the current folder under port 8000.
