Looking for a vintage ad style to inspire your design work, or just boost your party invitation's look? Google Blogoscoped proprieter Philipp Lenssen has assembled more 100,000 print ads from the last 150 years into a tagged, searchable database.
The ad images come from books, comic books, auction websites, Google's own online book and magazine offerings, and wherever else Lenssen could find them. The home page is sorted by category, but you can search through titles and tags using text terms at each page bottom.
Each of the images is owned by their respective creators or source material publisher, so the majority of images created after 1930 aren't game for your commercial use. That said, if you've got a private project, or just an interest in the history of pitching products, it's a great space to spend some time.