You could require people mail in their resume, which costs ~$1 within the US ($2-5 internationally depending on the applicant's location), and is a small amount of hassle without being a disproportionate burden on the applicant's time. The on-site prior to hiring is a good idea, but I expect you might still get some spam from people applying completely blind.
> You could require people mail in their resume That is supremely annoying for industries where applicants must average about 500+ submissions per successful job offer. I ran across two of those last year. Great-looking jobs, too. In a fit of pique, I submitted to one with everything typewritten using an Olympia SG3, and for the other I wrote out everything longhand. With a fountain pen. In cursive. It took me nearly…
I'm certainly open to better suggestions though.