It appears the US donations area is broken. Following PayPal from http://www.openbsd.org/donations.html, I am taken to http://www.openbsdfoundation.org/donations.html.
>From http://www.openbsdfoundation.org/donations.html, I select "US Donations" and then taken to PayPal. PayPal's site takes me to Canada's landing page. When I switch countries to US, the US states are not populated so I can't select my state from the dropdown. When I attempt to add my state to my city (i.e., Pasadena, MD), the form fails validation due to lack of a province.