Alright guys, I really can't advise about being able to ditch one IR receiver and use only one, I don't have an airboard. I have a Logitech RF keyboard/mouse combo. So I have that USB receiver and then I have the MyHD IR receiver hooked up to the COM port. Why do you two want to get down to one receiver so badly out of curosity?
I would imagine this is possible, I just can't say definetively. I don't know about a tutorial, not sure I have that much time and pretty much everything has been discussed in the forums before. I think your best bet is to download girder and start playing with it.
Here is a link to a thread that will give you a girder file for MyHD.
http://www.avsforum.com/avs-vb/showt...hreadid=149259
The only thing left for you to do is make sure girder can receive IR signals from the remote and then you just need teach girder the IR codes you want to associate with the event. Here is a good thread where people are working through learning girder and is what I used as a little crutch:
http://www.avsforum.com/avs-vb/showt...threadid=89462
Hopefully you should be able to search and maybe find a girder file for the airboard, haven't been down that road. Honest, an hour or two with Girder and you'll be a on your way.
clayfree -- you asked about the remote I used, it's a Sony Universal Remote - RM-AV3000. It's okay, there are a lot more resources available for the pronto's and they are definetly more customizable. Not sure the other differences, haven't really seen on in full action. But this remote does everything I need it to, I'm happy. And it was free since I have a Sony credit card.
I'll help out if you guys have any specific questions, but really a tutorial won't help that much, tinkering will

There is some girder tutorials at the girder website that will help as well.