I recently attempted to redirect a POST request being made by Apple's NSURLConnection. I say "attempted" because I could not find any status code that didn't make it revert to a GET for the subsequent request. 301, 302, 303, and even 307 didn't work. I finally ended up telling Apache to proxy the request to the real URL rather than trying to redirect the client.

(It is possible to override this behavior in the client with a bit of code, but I was trying to make this work with software that had already shipped.)