For U.S. manufacturers who use reps to sell their products in lieu of a direct sales force, here's a few resources you might find helpful:

• Manufacturers' Agents National Association (MANA) - MANA provides access to their agent member information and advice on how agents and principals can prosper together. Members include manufacturers' agents in all fields representing two or more manufacturers on a commission basis.
• Rep Hunter: an online rep recruiting service that is searchable by geographic region, specialties, education and more.