Canvassing voters in the electronic age

Bizcor sent me this idea for a post (Thank you):

“Obama has an app for iPhone that identifies the registered Democrats at the phones location.

That reminded me of the several political campaigns I’ve been involved in.  In the old days, a campaign would buy voter lists, identifying voters by party affiliation, address and phone number.  It could then use these to plan its door-to-door and phone campaigning.    The Obama app sounds like an updated, electronic age version of the same lists.  If he’s smart, Romney will have the same app.  In fact, I suppose all campaigns, right down to the local level, will soon have them.  What, if any, significance do you see in such instant access?