Front Pannier Racks
At AW Cycles you can find pannier racks from leading companies such as Topeak, Blackburn and Tortec that are designed to fit over the front wheel of a bike. They can be fixed in many different ways, with some attaching to specific braze-on clamps on the front forks and others able to attach with or without the braze-ons.
Practical Front Carriers
All of these racks are designed to carry either a front bag and/or front panniers either side of the wheel. Many will have a maximum weight limit so be sure to check before purchasing if you plan on carrying heavy loads.