[lcrim]

Ethernet can use the powerlines as a medium.  The Netgear devices can be used to tap into that medium   The Netgear devices can also encrypt those transmissions.  (This encryption can allow multiple network usage in the same building-office buildings for example.  There were statements in this thread that for home usage- your neighbors could receive your transmissions which is only possible if they share your breaker panel or knew your encryption keys. 
The power lines which are connected to your high fidelity devices would also receive ethernet packets (UDP packets are generally broadcast) and that may cause issues for sound.  Powerline filtering may mitigate these noise causing issues. 
Bandwidth in the newest devices is good enough for High Def (1080P) television and instaneous gaming.  I started this thread to show that wired connections for your Logitech SqueezeBoxes can utilize powerline networking.  The cost of the devices is not inconsiderable and must be measured against the increase in sound quality achieved by shutting off the wlan card on the SqueezeBox.  If you already treat your power for your audio, then this becomes more feasible.

[Bob in St. Louis]

  Wow Larry. That's one of the best, most clear, concise, accurate and helpful posts I've ever read. That spelled things out rather nice and tidy for me.
You win the "My Hero for the Week" award. 

As many problems as I've had over the years using wireless with my SB3 and Duet, I'm thinking the next time I have the slightest glitch, I'll be at BestBuy getting more "adapters".

Netgear should give you a kickback for that one dude. 
Thank you,
Bob

[lcrim]

Bob:
Thanks for the compliment.

[wilsynet]

Don't believe there's actually a noise issue with PowerLine networking.  Seems like a lot of FUD, with no evidence presented other than wild speculation. 

There isn't even an example of someone posting anywhere that there's a noise issue, just speculation that there could be.

Wilson

[PhilNYC]

I started using powerline networking in my home a couple of years ago. 

Life before installing powerline networking with regards to my audio system:
- Audio system runs completely on dedicated AC lines
- All components use some kind of AC filtering product (mostly Audience adeptResponse)
- Music source was Logitech Transporter used as transport to feed a DAC (Dodson Audio).  Transporter was being used in wireless mode.

I installed powerline networking in my home because my wi-fi network was not reaching all corners of my house that I would like (ie. could not get a reliable wi-fi signal in my bedroom).  The initial install only included using it with my computers.  I did not notice any effect on the sound quality of my audio system.

Later, I decided to see what would happen if I connected my Transporter to the powerline network (instead of using Wi-Fi).  There is an AC outlet near my audio system that is not its own dedicated line, so I used that one to connect to my Transporter's ethernet port.  The result was a noticeable improvement in sound.

So from my experience, powerline networking did not have a negative impact on my system's performance, and in fact bettered the performance as it related to my music server.

Just my two cents...