We purchased an Edgeport 8 port serial to USB adapter. We'll use these to console into various network gear from one central location. I wasn't sure how well they'd work in Linux but they work flawlessly. My Fedora 10 box detected it right away, and created the /dev/ttyUSBX adapter instantly. Pretty simple to setup and use.

May 11 16:23:21 localhost kernel: usb 1-1: new full speed USB device using uhci_hcd and address 4 May 11 16:23:21 localhost kernel: usb 1-1: configuration #1 chosen from 1 choice May 11 16:23:21 localhost kernel: io_edgeport 1-1:1.0: Edgeport 8 port adapter converter detected May 11 16:23:21 localhost kernel: usb 1-1: Inside Out Networks Edgeport/8 detected May 11 16:23:21 localhost kernel: firmware: requesting edgeport/down.fw May 11 16:23:22 localhost kernel: firmware: requesting edgeport/boot.fw May 11 16:23:22 localhost kernel: usb 1-1: Edgeport 8 port adapter converter now attached to ttyUSB0 May 11 16:23:22 localhost kernel: usb 1-1: Edgeport 8 port adapter converter now attached to ttyUSB1 May 11 16:23:22 localhost kernel: usb 1-1: Edgeport 8 port adapter converter now attached to ttyUSB2 May 11 16:23:22 localhost kernel: usb 1-1: Edgeport 8 port adapter converter now attached to ttyUSB3 May 11 16:23:22 localhost kernel: usb 1-1: Edgeport 8 port adapter converter now attached to ttyUSB4 May 11 16:23:22 localhost kernel: usb 1-1: Edgeport 8 port adapter converter now attached to ttyUSB5 May 11 16:23:22 localhost kernel: usb 1-1: Edgeport 8 port adapter converter now attached to ttyUSB6 May 11 16:23:22 localhost kernel: usb 1-1: Edgeport 8 port adapter converter now attached to ttyUSB7 May 11 16:23:22 localhost kernel: usb 1-1: New USB device found, idVendor=1608, idProduct=000f May 11 16:23:22 localhost kernel: usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=5 May 11 16:23:22 localhost kernel: usb 1-1: Product: Edgeport/8 May 11 16:23:22 localhost kernel: usb 1-1: Manufacturer: Inside Out Networks May 11 16:23:22 localhost kernel: usb 1-1: SerialNumber: V13621972