[jogzden]

I don't really see the point to Twitter for hiring purposes.

But both LinkedIn and GitHub serve as e-resumes. Any decent tech company will want to see what you've worked on/contributed to, and a lot of the time and dev worth their salt will voluntarily provide their GitHub on a resume. LinkedIn, even though it's more social than GitHub, still serves as a professional site. You don't voluntarily put your information on LinkedIn only to hide it from potential employers.