I think there would be interest in having a downloadable image file that a reader could print and post in their office or wherever. It should be printable at no more than 8x10 to fit in a dollar store frame. It could be one of the many curiosities you write about. Maybe maps, maybe odd photos such as the Victorians pictures posed with dead people. No copyright issues. Also, the photo could be tagged with your website inviting a passing observer to join up. This makes your readers your marketers.