Congress should have a similar system, perhaps one for each representative and each senator. They could get a better sense for what the people they represent want. Rather now that's only done through e-mails (which probably never get read by the politicians themselves), phone calls (same thing, and a bit inefficient considering most people won't bother to call), and visiting in person (probably done by very few people).
They could even be done in a sort of Google Moderator/Reddit way, although perhaps more fine-tuned and with certain thresholds (but not too high, especially initially).
This would be great, though you would need some way to tie people's accounts to their residences, which would require them to work with boards of elections give out the elections with the voter registration receipts.
I fail to see a problem with voicing your opinion to an elected official, even if that person is not representing you. Especially when one state making a decision can set a precedent for others.
Although I do think that the votes should be tied to location, even if other locations are allowed in. I think a ZIP code is enough here; it's a letter, not a vote.
Why should a representative care about the opinions of people who aren't voting for her or contributing to her campaign? There are lots of opinionated people on the internet.
I simply picked the board of elections because they already are entrusted with the capacity to verify that a certain person lives in a certain ward or district. I suspect zip codes would not be fine-grained enough for local government fora, where this would be most useful.
They don't have to weight everything equally, but as I previously stated, politicians that actually want to do good and not just get re-elected (I hear some exist) might actually care about their precedent-setting decision and how it will impact non-residents.
I think there is certainly value in outside voices. Journalists and bloggers play that role now. I guess the issue I have is that any given district could get suddenly swamped by outsiders. Why not have it be the case that constituents would bring that voice in by linking to their post?
One idea that I have some sympathy toward is making the representatives responsible for moderating the fora as they see fit. They would then be judged at the ballot box if they pissed everyone off...or they would really skillful at creating false consensus.
They could even be done in a sort of Google Moderator/Reddit way, although perhaps more fine-tuned and with certain thresholds (but not too high, especially initially).