I have made an imp powered 1-wire master. It uses a DS2482-800 bridge. There are 8 channels, 4 are wired to RJ45s and 4 are available on a pin header. The power regulator is on board and supplies 5v regulated and unregulated supply to the RJ45s. I have written code that will read DS18B20, DS18S20, DS2423 and DS2438. It is easy to extend this to other 1-wire devices.
The PCB is fitted into an enclosure. I have a limited number of these available now, I can make more on demand.
If you would like one or have any questions, please contact me.