Birders throughout the U.S. and Canada often become avid twitchers for birds that are uncommon or rare in their county. eBird is the online site where a large portion of North American birders record their bird sightings, and often have a friendly competition to see who can find the most species of birds in their county and their state every year.
A great online tool to help look for these rare birds is a website called County Rare Birds http://countyrarebirds.com
On this site if you register the site automatically opens to your state or province and county of choice. You can then browse easily to any other state or county in the U.S. or Canada to see what rare birds have been seen there in the last 2 weeks.
It is a tool you can use in addition to the alerts on eBird, where an email is sent to you every day (or if you prefer every hour) when a rare county bird is reported.
Here is a screen shot of how CountyRareBirds.com opens for me:
As you can see this opens to my chosen Pierce County, Washington state. The display is of all of the rare and uncommon bird sightings seen on eBird in reverse chronological order, most recent at the top. You also see the number of individuals of that species reported, the species name, the location of the sighting, the date of the sighting, whether the sighting is confirmed by eBird reviewers of not, a link to the eBird checklist and the name of the birder reporting the sighting.
One of the coolest parts of the CountyRareBirds.com site is that it is a real-time list, with reported sightings showing up on the site almost immediately after they are submitted to eBird.
I hope you find CountyRareBirds.com useful.
Good birding.