I seem to remember a site that would give you your congress-critters` name and contact#s with just the state and zipcode,someone posted the link during the 2004 election cycle.
The problem I have noticed with a lot of Congressmans sites is that they don’t receive regular email. You have to go on their page and send it through their page. Before you are allowed to do that, you have to enter your zipcode. If it detects that you are not from their district, then it doesn’t let you send.