The Federal Government's flagship National Broadband Network has had its grand opening on the mainland, in the NSW city of Armidale.

Already going through the testing phase in the Tasmanian communities of Midway Point, Smithton and Scottsdale, the NBN will be tested in several mainland 'First Release Sites' over the coming months.

"Today marks a significant milestone in our national rollout. Residents in Armidale will be the first mainland Australians to experience the tremendous benefits of this vital communications infrastructure that will serve Australian homes, businesses, schools and hospitals for decades to come," said NBN chief executive Mike Quigley.

With regional Australia having to put up with what communicationsminister Stephen Conroy dubbed as "very slow, very expensive and very inadequate telecommunication services," property investors will be keenly eyeing up the NBN's progress to assess whether such a major infrastructure improvement will have a positive economic impact in regional communities.

Further mainland cities set to head into the NBN testing phase in the coming months are Kiama/Minnamurra Downs (NSW); Townsville (QLD); Willunga (SA) and Brunswick (VIC).