That's why I posted this message -- since this technique appears to work in certain cases (i.e. one user here uses a plain AT&T phone plan without a Blackberry plan. They get no access to AT&T BWC but has no problems with BES/MDS).

I am trying to collect information on users doing this "Bring Your Own Access" technique so that a FAQ can be made, or that my BES/MDS Hosting FAQ can be extended to include this information.