For those following along, the SSL/HTTPS suggestions for websites is now in full effect, and confirmed by Google as a ranking factor. It is the goal over the next year to also have EVERY site using HTTPS, not just for security of ecommerce transactions, but rather to stop potential man-in-the-middle type attacks. Security is a big concern.
Twitter & Facebook - sure, post away on there, but they're not directly influencing SEO. They do influence traffic, but they don't directly affect ranking positions.
Press Releases - forget about them. They're no longer relevant for SEO rankings. Again, you can definitely get traffic through them, but they're useless with regards to increasing ranking of particular phrases etc.