PeteK... A dongle is just a little ir transmitter on the end of a wire that can be plugged into the usb-uirt and stuck to the front of an a/v device. The usb-uirt has a built in transmitter as well, so you could just have it face the components, but dongles work better plus you can splice and have 4 or 5 of them all attached to the front of different components and responding to different codes. So you could control all of them with 1 usb-uirt.
danielk... I understand your concern about getting the codes learned properly, with earlier releases I had problems figuring out the sweet spot as well (new batteries, proper lighting in the room, proper distance, proper key press, etc.)
I can get the device to function as required with irhelper.exe in windows. In fact I programmed up, down, left, right 0-9 and enter. With one failure...enter so I had to do it a second time.
For some reason I cannot get 0710RC2 to control anything, I just aint a coder, I'm torrenting 0710RC1 right now, because I think that one works. I just want to keep on testing.