If they have an iPhone, why not just send it to their email address? (which is what you would do it they had a PC)
Alternately, if you know their phone number, you can send it to firstname.lastname@example.org
Note that the BlackBerry example you gave is an instance of that user having a BlackBerry email address on their BlackBerry. Not really applicable to someone with an iPhone. If they had a BlackBerry on Verizon, they might have a corresponding Verizon email address, but not with an iPhone.
File size matters. It has to be under 1000kb of them to get it.