I have USB-UIRT too and love it, I bought directly from the developer.
I think this was originally a do it yourself kid and OS firmware but as time went more bought for fifity rather then soulder and splice for $39.
The USBUIRT supports 3 seperate zones so you can control 3 of the exact same setup (TV+VCR+Cable Box) independently. It's often used to control multiple Sat or Cable boxes by PVR software, the cable boxes often have a single set of IR codes so to make 1 out of the stack of 3 change channels you'll need indepentent zone control. EventGhost provides this without trouble, as does SageTV.
Zone 1 is IIRC the left audio channel from the 1/8" stereo jack on the back of the unit.
Zone 2 is IIRC the right audio channel from the 1/8" stereo jack on the back of the unit. (could be backwards)
Zone 3 is the front mounted emitter, yeah I love taping this to the front of the 3rd cable box!!! (see rant #1)
No zone provided fires it to all zones.
What I don't like about the USBUIRT...
It seems development is dead, how old is this hardware design?
You get 3 zones but 1
MUST fire from the front??? It would be nice if that was another 1/8" jack with a jack>LED adapter in it.
Why not more zones? Everyone supports it already if a new design were released surely support for that would spread as well. With the growing HTPC and automation markets if Rhees doesn't make something someone else will (already have but not widely supported and much more $).
Uncertainty in regaurds to installing 2 in one system, this could help #2 at least you have 4 zones that way (4 cable boxes is not unrealistic today!)
That said I bought one no so long ago, I still like mine, it has been a solid device and I will continue to suggest them when queried. Those issues just stivk in the back of my mind.
Powermids:
http://www.smarthome.com/8210.html
This are mearly wireless IR over RF, whatever you shoot at one powermid comes out the other up to like 100' away. They seem to work okay I have one in my spa that passes IR into the bedroom to control the MVP client providing video in there. This way I just have an LCD and a powermid plus AV cables between, however you must watch whatever is on the bedroom TV. Handy devices but you could just run a wire from the USBUIRT or use something like Xantech, ChannelVision or ChannelPlus hardware IR distribution. It depends on how many ins and outs and how far apart and whatnot. I think one has an over your existing TV coax solution which is nice as coax is usually already at the TV locations. Quite possible you could fool a reciever into transmitting something that didn't originate at the other unit or making IR have it transmit RF that isn't only recieved by the other powermid. Interesting stuff I know nothing of.
Interested though I have 2 sets and RF x10 transciever so it could be quite cool and require no PLC or RS232 just a USBUIRT pointed at a powermid RF transmitter.
EDIT: The transmit and recieve quality of the USBUIRT is top notch! You might think you have an RF remote for it's reciever and to control my amp and changer the IR gets bounced off some dark blue cloth to get there. Never a touble. Learning codes could be slightly better but I am unsure as to where that difficulty lies, could be the room lighting or LEDs on the front of devices surrounding it.
