Thanks for the info, the details of what I want to accomplish are pretty simple, just want to use the tiny second remote that came with the AVR to change two things - volume and FM tuner preset. It does both well when I go sit in front of the AVR already, so that's good to go.
I guess what I'm trying to figure out is whether it's worth the cost to bother with IR at all since I can use the web interface of the Yamaha via an iPhone to do everything I want. I'd like to do it for ease of use when visitors want a turn with the remote. If I can control the receiver by installing an IR sensor outside that can be plugged directly to the AVR, that is definitely worth the cost to me. If I have to also get a distribution / connecting block to relay, translate or otherwise intermediate between the sensor and the Yamaha, the cost of the gear as well as the hassle of coming up with a way to get power to it, where to mount it (the AVR is out in the open essentially, no closet to hide this in as a result) then it's very easy for cross it off the list of worthwhile projects at the house.
Somehow I completely missed the bus on IR relay technology, so I appreciate you taking the time to help me with something that I'm sure even newbies generally understand without having to ask...