There is an overview of Ephemera in the University of Glasgow on the Special Collections pages and a link to the Scottish Theatre Archive online catalogue which contains much material from the University of Glasgow ephemera collections. There is also a very useful introductory page to the Scottish Theatre Archive, with Flickr slide show and a list of collections included in this resource.
The Social history page describes collections of Chapbooks and Broadsides as well as named special collections including ephemera, notably Euing (temperance), Murray (broadsides, street literature, chapbooks and advertisements) and Smith.
The Ephemera of John Smith is an online exhibition by Adam McNaughton. John Smith collected ephemera received in the course of his career (bookseller, town councillor and estate owner). Initially bound in albums, it is now arranged by theme: Transport, Political, Church, Trade, Entertainment, Crime, Education, Medical, and City affairs. The ephemera relate mainly to Glasgow in the first half of the 19th century. The online exhibition shows ephemera representative of each of the themes, with explanatory text describing the item and its relationship to the collection.
Glasgow Broadside Ballads: the Murray collection is an excellent introduction to and teaching resource for ballads from collections at Glasgow, and indeed to ballads in general. There is an index to the ballads in the collection with linked images, sound files of ballads being sung, introductions to ballads and the oral tradition, publishing and selling ballads, ballad consumers and singers.
Other online resources of interest to ephemerists are: Seaside entertainment (an online exhibition of postcards) and a Flickr featuring Victorian Christmas cards.