humvee:hookflash *44 seems to work ok but it seems to only allow an unmannaged transfer there you cant hold on and talk to the person you are transfering to before putting the call through

*44 is blind transfer, to do a managed transfer you can do:

hookflash
Call 3rd party
Say blah blah blah
hookflash - now all 3 callers are joined
Hangup - now caller & 3rd party stay joined