Have just recently received my USB UIRT from Jon which arrived in quick time from the States to Melbourne Oz (4 days)....Must say having played with it and the Girder Software over these last few evenings im very impressed with it ....
The reasons for purchasing the USB UIRT was twofold ...
1: To expand my ha ir capabilities as Homevision has a limit of 256 ir codes.........
2: Secondly to try the USB UIRT on my recently designed cat5 based ir repeater system which will allow ir input from several rooms...My initial thoughts was that the USB UIRT would only be allowed to send ir to the repeater system using scheduled events..But what i thought would be nice is that the USB UIRT could transmit ir in reponse to receiving ir...Wasnt too confident that this would be achievable as the signals would collide/ overlap...But thankfully in the "settings"for each ir command in the Girder USB UIRT PLugin there is provision to have a delay period before transmitting ir....thus the signals dont overlap providing the user does quick short presses ...As a test i am using my HA Remote to mimic my dvd remote and it works quite well

If linterested in having a look at my FirM Jr repeater have a look here
http://skybax.rapidhoster.co.uk/~armagh/page80.htm
Also the xPL Developers are currently working on a plugin for it....
http://www.xplproject.org.uk/
Frank