A team from the ETH university library in Switzerland has digitized what they call the "Construction Memory of Switzerland" ("Baugedächtnis Schweiz Online" bzw. "Mémoire du bâti en Suisse online") - essentially two architecture and engineering magazines: tec21 and Tracés. Both are available for free at http://retro.seals.ch/digbib/collectionsHome2.

This archive gives free access to a wealth of semi-recent (2005) and historical information (back to 1874) and provides fulltext PDF downloads (including the ads). The only item on my wishlist would be better (ZINIO-Style pageflipping) navigation. But I am getting greedy...