Excellent uses for netcat at http://www.foureleven.org/pub/nc/

This shows what's needed in a POST.  N.b. the length is required!
http://www.jmarshall.com/easy/http/#othermethodshttp://www.jmarshall.com/easy/http/#othermethods

See file java/encoding.txt too.

HTML forms ALWAYS HTTP encode param names and values (e.g. from <input>
names and values).  Therefore, it is thoroughly safe to use special characters
in http input element names (and, obviously, values).

"get" mode forms (default) send no Content-Type

REDIRECTS
When a client gets a redirect back, they make the new GET request with params
exactly as given in the redirect.  They do not-resened params of the original
request.  If that's what the server wants, then it needs to return the original
params back to the client in a new query string.

At least with FF, get-method posts silently drop query string on the action.
Kinda funny that the params are preseved if method is post.

Accept header value is perfectly encoded just like you would want it to be
(of course with the top-level ?, =, & not encoded so you can parse GET params).