But the difference is that the 'software geeks' are the ones in demand in this senario. A geek does not typically approach an outsider and say 'I've got skills

But the difference is that the 'software geeks' are the ones in demand in this senario. A geek does not typically approach an outsider and say 'I've got skills can you come up with an idea for me?'. But on the flip side 'you have skills, I've got this idea' is a -very- common occurrence. If you are the one doing the approaching applying your own quality control is a given. If against the odds you are being approached by an unknown geek wanting to partner with you, then testing their skills should be part of the process yeah, you both have to be confident in each other; though I would consider the above methods to be a truly terrible interview...