if my 'new http method' you mean something other that GET, POST, PUT, etc then no, you cannot (in Apache 1.3, at least).I was wondering if it is possible to write a handler to handle a 'new http method', because I could not find any hint in the user guide. :)
just about the only thing you cannot do with mod_perl is parse the Request Line - that is handled by Apache before the request cycle starts. so Apache will intercept the requests before the PerlPostReadRequestHandler runs, similar to the way it intercepts HTTP/1.1 requests without a Host header.
in Apache/mod_perl 2.0, you can write an input filter that _does_ allow you do parse the Request Line yourself. then again, you can write a protocol handler for any protocol you can dream up, so there's no reason to mess with HTTP :)
--Geoff