I've managed to get my hands on an Ontrak ADU-218. It's a nice little unit that gives 8 x computer controlled relays and 8 x logic inputs using anywhere from 5-24v as a 'high'. This is a USB product, and seems to work very well! I've got it going under Windows with their supplied DLL file, however I'm trying to get it running under Linux now (it seems to be a HID device). John Homppi has done a bit with this in the past but I can't find anything since. Hopefully John still checks his mail! Update: John has pointed me to his site!