Just in case not everyone is familiar with this site http://www.dealextreme.com/search.dx/search.servo this is where you can get some cheap servo motors. Not the best quality, but the price isn't overwhelming either.
At the same time they got some servo extension cables, which can also be used to connect bricks to the arduino shields.
300mm http://www.dealextreme.com/details.dx/sku.11985
300mm http://www.dealextreme.com/details.dx/sku.11984 (splitted)
500mm http://www.dealextreme.com/details.dx/sku.11986
1000mm http://www.dealextreme.com/details.dx/sku.11987
Notice that there can be voltage drop, depending on the length and quality of the cable. 