The creation of an online portal for citizen participation would be an institutionalized government portal that would allow citizens to research, discuss, and oversee formation of public policy as well as locate and log community service.
The closest thing to this so far would be a hybrid of the creations of the Sunlight Foundation, primarily OpenCongress.org. It would provide a portal for citizens to review and comment on proposed legislation and track government accountability (such as donors to their representatives). However, institutionalization will help get members of government and their staff interacting with citizens.
For example, on the government side there should be functionality that allows a representative to filter out all comments to find those posted by their constituents. They could also allow twitter or RSS to rapidly take surveys amongst constituents. Filters could also be used to find expert opinions by filtering out constituents to see what lobbyists or academics are saying about a bill. Combine these filtering options with data visualization tools will make it easy for representatives to tap into the public consciousness and citizens to have a dialogue with their government on issues of the day.
Another filter would be to adjust the scale on which you are viewing. Be able to toggle between the district, state, and national discussions so you can find issues more relevant to your specific location. This could also be used to find local volunteer and public service opportunities. Furthermore, each opportunity could use a standard form to log hours of volunteers, so your citizen profile could show not only how active you are online but also how active you are in your community. This would be a great way to get credit for civic participation.
There are many more ways this could be more efficient. Please provide feedback in the comments section.