I`m no expert but i`m sure the max is about 100m
I run a 30 foot one to my sons room and use a 2 foot one myself and unless your chasing down every last ms i think you`ll be fine.
I certainly dont notice any great difference
EDIT:seems you can have up to 500m if you have the right kinda wire
http://www.homenethelp.com/web/expla...ble-length.asp