LinkedIn is my default resume. If a company/person I'm submitting to pooh-poo's my Google Doc with accomplishments and links to YouTube etc. plus my LinkedIn profile and wants a paper hard copy it's a pretty good indicator the fit/structure probably isn't right for me.

This is a guideline though, not a hard-line determinant.

If the company DOES seem like a good fit and still wanted a paper resume, I just copy/paste my LinkedIn data there.

And, if you want to network with a generally older 'gray hair' crowd, they may not be on Twitter (but probably Facebook) and think Foursquare is a playground kids' game but most likely will respond to your requests on LinkedIn.