in regards to Github, if Git is used already in the company's development process, the candidate would need to show that he or she is familiar with Git. Then Github is the first destination to show that. On the other hand, of course there are plenty of other Git hosting opportunities -- sourceforge, for example.
"if Git is used already in the company's development process, the candidate would need to show that he or she is familiar with Git"
Any company that requires a potential hire to be familiar with their current source control system is an insanely stupid organization.
Not if it's my code. I shouldn't have to open source my own code just to show it.
at the moment I rent a minimalist VPS for about $35 a year and use gitolite to organise my private repos. Works perfectly so far :)
I'd prefer it if they'd just say, "send us a sample of your work, or a link to your source online."