Is the developer I'm hiring as good as he says he is?
How do you know if the person you are interviewing is as good as he says he is? Is their some sort of standardized test for code writers that a business could use to help out in this?
If they are a college grad, they are probably trying to get their foot in the door anywhere. Tell them they can intern for a 2-4 weeks, and if they do well they will be hired full time.
Alternatively, you can hire them on blind faith. If they are obviously lying about their qualifications, you can blacklist them in a blog entry (trust me, no one wants to have their name come up with bad results in google). Of course, warn them first that if they are lying about their qualifications, you will make this public knowledge. Either they will be confident enough to continue or you will have filtered out one unwanted candidate.
The last way is just to hire them, no questions asked. 99 percent of the time, they will make great employees, even if they struggle for the first month. I was hired with no knowledge of Flash out of college to work on a Flash-exclusive project that already had 10s of thousands of lines of code. In the end, I turned out to be a valuable employee, despite being severely unqualified.