As of now you can use the phone functions of  an unlocked Blackberry on
Fido.  However, Fido's data plan cannot access the Blackberry mail
server. Maybe we should all lobby Rogers/Fido's CEO.

You can buy an unloacked blackberry and put it in their network, you need to
call Blackberry and tell them to put RIM on th eline so that they can put
the blackberry's IMEI in roger's list. I just had to talk to lots of people
to do this. But one key note was that I was an existing Blackberry
subscriber prior to asking them to add another unloacked blackbery under my
name.

Did you buy the one from Factory Direct in Canada? They are from Cingular
and yes you need rogers and rim to make the changes.

Thanks,

RdR