HBO’s release of the teaser and their opening of the official site for the series—an unprecedented move for a series almost a year out from airing! Straight from the sight are a number of high-resolution images of Ned Stark, perfectly suitable for a widescreen desktop or mobile phone:
They’ve also released a Quicktime version of the teaser which is slightly higher quality, which can be downloaded here. Thanks to paulo at WICblog for digging these out.