The draft http spec already defines both a Redirect and a NowGoHere.
The redirection code
301 Moved Permanently
signifies permanent redirection; clients are encouraged to remember
the it, and the code
302 Moved Temporarily
signifies a redirection that may be dynamic. The draft spec implies
that redirection information gotten in a 302 response may never be
cached, though I wonder how many clients conform to this part.
I've been writing on a draft spec commentary which suggests that the
expires header may be used to allow control cacheability of 302 (and
300) responses.
Koen.