I always hated printing. Now that I've moved my office, I don't have the option of printing something right now, because there's no working printserver yet. I'd also rather not fall back to printing out stuff just to then scan it in order to add a signature to a document. That just feels wrong.
Recently I switched from using a Macbook Pro to a Chromebook Pixel and I am no longer able to use the wonderful feature of Preview.app where you hold your signature into the iSight and it transforms it into a vectorized signature that you can add to any PDF you desire. So, after trying a few online services, I found HelloSign to work quite well. They don't require a Chrome extension, offer 3 signatures for free per month and support logging in using a Google account: You select a PDF from your Google Drive and add a signature using either a pen or your fingers on either the touchpad or a touchscreen. You can modify the signature's size and put it wherever you need it to be.
Because Google still doesn't allow you to limit the scope of Google Drive-access to 3rd parties, I've removed their Google Drive-access after using their service, just to be sure. If you're not into using Google services, you can also just create a new account and upload a local file using your browser.