It was for ANY carrier and Any location within the US. I believe it was a push right around when the Pearl came out.
All you had to do was buy a Blackberry device and activate it and RIMM would verify you and then have the partner travel agency send you a voucher, good for us to one year from date of issue. Mine expires in Feb of 2008. BlackBerry Connection - Personal Edition - October 2006
The promo website is dead now, but the deal was real as shown by the link above.
This was nationwide. I'm surprised no one took advantage of it.
UPDATE: I just rec'd an email from the API travel agency saying they were able to locate my certificate/enrollment. I'll call again and se if I can take advantage of this deal and report back.