So far its a little odd.
The concept in itself is pretty interesting. Although the data that show up on the locational services is different depending on whether I am using my Nexus7 tablet or my HTC Thunderbolt phone.
You need a data connection to report properly and actually see elements on the map properly. So tablets really won't work for this type of thing at the moment, unless they update it later on.
It is typical that in most rural areas there are no portals close by...and there is no way I know to search out where the closest is. You have to explore. But typical posts on the chat channels seem to indicate they are on standard buildings occassionally like post offices, libraries and tourist spots. The intro gives you an idea what you have to do, but I haven't found a use in my rural area where there is an actual portal to activate/hack. I'll be giving it another shot, but right now all I can do is drive around with my HTC Thunderbolt and collect energy. Of course, the Nexus7 sees a lot more energy when I load it up on the screen from wifi in the room around me. Not sure why the differences, but I can't use that one.