Pennsic Traceable Art Project, compiled by Ailis Linne
This project was begun as a response to the volume of heraldic art being sought every year at the consult table at Pennsic. The heraldic artists there were being worked overtime and then some, often on the same common charges. There are many charges of varying sizes...trace away!

http://www.aeheralds.net/Links/AE_Traceable_Art/TraceableArt.html

Free Heraldic Clipart, compiled by James Wolf Heraldry
Many of the pieces come from Fox-Davies and Pimbley, both Victorian-era heraldic artists, and some depictions aren't quite accurate for our heraldic scope (for example, the "wavy" seen here is hardly wavy at all), but there are a lot of images, arranged alphabetically.

http://www.heraldicclipart.com/

Catalogue Of Period Devices, compiled by William Castille
This book contains over 1300 blazons and emblazons of period devices taken from a number of period rolls of arms that found on Brian Timms early rolls of arms website (www.briantimms.com\era\early rolls of arms.htm). They are all black and white outline as the compiler, from the Kingdom of Lochac, is more interested with showing the layout and design of the device than the colouring, as the object of the collection is to give people an idea of what period style is. This book is supplied free of charge and may be freely copied and distributed. It is not to be sold for profit. Be Warned: the zipfile is over 6meg in size and expands to a pdf file.

http://heraldry.griffin-dor.org/catalouge.html

Brickbat's Armorial Stash
This is a growing number of armorial bits and pieces, taken from many sources (the Pictorial Dictionary, Fox-Davies, excellent depictions of charges that come through the SCA College of Arms, anything that might look useful "for later.")
WARNING!!!! This is a 25MB file that expands into individual files.
http://atensubmissions.nexiliscom.com/ClipArt2.zip