After doing lots of research, I have come up with a solution:
You can sign up for T-Mobile with blackberry only data + $19.99 unlimited int'l blackberry, giving you unlimited data and email while overseas (or in Canada!) You roam on Rogers and Fido flawlessly, and you have UNLIMITED data, not "unlimited" like rogers has...

I am a T-Mobile dealer myself, and am giving BBforums users $50 off a bb 8700g via a credit on their account and waiving the $35 activation fee.

Shoot me a PM, and ill set you up!
my screenname is The Mac Ace on howardforums, so you can see my flawless feedback there

But you would have to get a non-local Canadian cell number, right? And those calling into that BB would be calling long distance, to the US, right?

hence it being data only

Data on TMo, voice on rogers via a second phone is my guess....

yep thats teh idea

Isint it illegal for a person to buy a us cellphone and live outside of the states with it? I can see tmobile cancelling someone out because 100% of their data usage is outside of the country. And how would they go about collecting the 200 dollar cancellation fee?

It's a risk they take. In fact, I was only approved for IN COUNTRY usage on Tmobile...even though they used my Canadian SIN. It is not illegal. Not all Americans, with American Credit, live in the US.

Also, Equifax is Equifax. If you don't pay, they'll get their money. Don't you worry.

I'm in --- i'll be contacting you shortly.

can i get more details i have contract with fido 30$/month and i just got BB 7290 with rogers data paln on montly base no contract 40$/month.

Wirelessly posted (BlackBerry 8700c: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0) BlackBerry8700/4.1.0 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102)

Your title is a little missleading. You make it sound like those using Rogers can get unlimited data while staying with Rogers, not switching to T-Mobile.

Not that it really matters to me since I'm with Cingular.

I don't think it works. The reason I say this is because I tried this more than a few months back.to I visited 3 locations when I was in the US last time (2 T Mobile and 1 Cingular store) At both T Mobile locations I was told that when T-Mobile notices that all my usage is in Canada only they would deactivate my service with them. The Cingular rep I dealt with was new and couldn't get a hold of a support department to answer my questions. I will be signing up with Cingular for a voice plan anyways with no contract as I will be going to the US quite often now for work and it's cheaper than the US add on package Rogers offers and with a month to month plan it will save me more money than always refilling with pay go. I may just get a voice and data plan with Cingular. My Rogers bills can be anywhere from 300-700 dollars in data overages at times. I am just glad that I am partially reimbursed for my BlackBerry use from my company.