OK, trying again not to get my nerves too twisted up, but most of the answers here are from people that haven't read the RFCs.

The HTTP RFCs permit the use of

Method: POST
[download]

to change the method on the redirect with location. Admittedly, this is used mostly for changing from POST to GET, but I don't see any reason why this wouldn't work in the other direction.

-- Randal L. Schwartz, Perl hacker