The West Nile Virus is expected to spread into Utah this summer, so it now has its own website with a growing volume of information and a dedicated West Nile Virus manager in the Department of Health. I've already learned a few things from the site. The Department of Natural Resources has put together this excellent presentation on Utah birds and the virus. The CDC reports that 138 bird species have died from West Nile. Tennessee has a map of all the positive bird cases throughout the state. Ted Ritzer shares some great information on the top birding sites, some of which are government-sponsored.
Right now, if you look at the map, Utah is still one of only four mainland states without a reported case of West Nile. Pennsylvania has an excellent West Nile surveillance system and you can have any updates sent to your email box. Dead birds are already showing up in Lehigh County. The National Atlas has an entire series of West Nile maps, including this flash version for New York City that lets you mouse over to see cases for humans, horses, chickens, and wild birds.
Illinois has an excellent online brochure for protecting your home against mosquitoes.
Although there continues to be some speculation about whether West Nile was introduced accidentally or intentionally into the US, the CDC sees no evidence of bioterrorism.
West Nile as a study case for risk communication response - Center for Risk Communication