Possible to "move" workitems to selfdefined folders (4.6c)?

[Tom Olaf Bakke @ Spring]

Hi.
 
Is it possible to create "folders" in the business workfplace and place
workitems there, or are the predefined groupings according to task etc the
only possibility. The requirement would be to devide up many workitems of
the same task in order to systemize them according to why processing must be
performed later.
 
Thanks
Tom Bakke