Sagas in Miniature blog offers three free download-and-print Dark Ages Scot banners.
flag
Viking Flags
The Man Cave has a couple of printable Viking flags.
Roman Vexilla (Flags)
From the Red Rampant site comes an article on Roman Vexilla (flags, or standards). Useful information for anyone building a Warhammer ancients army of Romans.
Lizardmen Fantasy Banners
The Grimsby Wargames Society has a nice selection of Lizardmen Fantasy Banners.