Amazon.com: ATEN UCE3250 4-Port USB 2.0 CAT 5 Extender (up to 50m) : Electronics
Amazon.com: Aten Corp 4 User 2 Port USB Hub (US224) : Electronics
ATEN UCE260 USB 2.0 Cat 5 Extender 672792005985 | eBay
USB 2.0 4 Port Peripheral Sharing Switch US224 ATEN, USB 2.0 compliant, support Windows, Linux ,Mac and Sun, Overcurrent protection, Hot pluggable, UK #1 KVM Market Leader - PC Maestro