HTTP Authentication

[Dale Peakall]

Any suggestions on how I might approach triggering HTTP authentication 
when a specific exception is thrown from a service using the HTTP 
binding?  If I could simply let the exception propogate to the servlet 
container (without being turned into an XML fault message) then that 
would be best for me (since the servlet container is already set-up to 
handle this).  Other suggestions are welcome though.

Thanks.