Erm, that should be 'from', not 'form'
One feature my users continually ask about is copying attachments from mail to mail. They had this before and miss it in the AJAX interface. e.g. pdf scan attached to incoming mail, copied to new outgoing mail to send out.
At the moment I have to tell them to save in somewhere and re-attach it. When I get round to moving to 6.0.1 (or .2) I know I'll have 'save to briefcase' and 'attach from briefcase' but I want to bypass any save/attach that will leave extra files around the place.