S.Tindall wrote:
Tripp-Lite U209-000-R: http://www.tripplite.com/products/product.cfm?productID=2430
Cables-To-Go 26886: http://www.cablestogo.com/product.asp?cat%5fid=101&sku=26886
Think they cost about US$15 each at provantage.com.
I've been using these with zero issues ( 14 of them connected to one machine ):
drivers/usb/serial/usb-serial.c: USB Serial support registered for ark3116 ark3116 1-1:1.0: ark3116 converter detected usb 1-1: ark3116 converter now attached to ttyUSB0
about £3/each, totally unbranded from Tottenham Court Road, London :D