When I think of the typical wingnut, it's pretty much this guy. But for what it's worth, let's debunk a few of his ridiculous, paranoid claims via FactCheck.org:
Birth Certificate / Born in the U.S.A.
Recently FactCheck representatives got a chance to spend some time with the birth certificate, and we can attest to the fact that it is real and three-dimensional and resides at the Obama headquarters in Chicago. We can assure readers that the certificate does bear a raised seal, and that it's stamped on the back by Hawaii state registrar Alvin T. Onaka (who uses a signature stamp rather than signing individual birth certificates). We even brought home a few photographs.
And...
In late July, a researcher looking to dig up dirt on Obama instead found a birth announcement that had been published in the Honolulu Advertiser on Sunday, Aug. 13, 1961:
More debunking of the lies about Obama's citizenship here.