I recently stumbled on an incredibly wonderful website; one that threatens my productivity just as much as Wikipedia does. The Vintage Ad Browser is a trip down memory lane, showcasing magazine advertisements from as far back as 1800. All kinds of categories are available to peruse: from Airlines & Aircraft, to Gender (some of which, today, are quite sexist), to Transportation. This site is one of those black holes on the internet, where you can get lost down a trail of links. I highly recommend checking it out; definitely worth bookmarking.