Media in the 21st Century
You plug one directly into an electrical outlet near your Internet access point (in my case, in my home office). You run a CAT-5 (ethernet) cable from the PowerLine to your switch, hub or router (whatever you're using to connect to the Internet).
You plug the second one directly into an electrical outlet near the device you want to connect to the Internet. You run a CAT-5 (ethernet) cable from the PowerLine to your device.
One note: you need to make sure you do have a free electrical outlet. You can't use an extension cord or powerstrip. So we did have to move some things around and get a new powerstrip to free a nearby electrical outlet.
We did this we were shocked when it actually worked! Especially considering that our house was built in the early 70's and nothing is standard in it. I honestly didn't think it was going to work.
Next step: a device that can stream video.
The little ROKU looked just about right and was within my price range (under $100) so I got one of those. And was seduced again, this time into getting Amazon Prime which offers free, 2-day shipping and free video streaming. :)
We got the ROKU XDS. It's just a little box with a remote control. I was really torn between this and the GoogleTV device, because the GoogleTV has a keyboard which is nice for poking in titles you want to search for, but...I'm a cheapskate.
The ROKU was just as easy to set up--I plugged it into the TV using an HDMI cord (I purchased that separately). I plugged it into the PowerLine. Then I went through a few setup steps to tell NetFlix and Amazon that I had this nifty little box to stream video. There were a lot of other services, e.g. HULUPlus, etc, but I figured NetFlix and Amazon were enough. (I'd eventually like to get down to one service, but right now those two compliment each other pretty well.)
Now, we can stream video from either NetFlix or Amazon. When you select something, there is a slight delay as it initially buffers your selection. This generally runs a minute or less. After that, it's just like watching "real TV". There are no delays, no jerkiness. You can get HD if your television is capable of it (ours is so we do use that). Both NetFlix and Amazon have search boxes that pop up a small alphabet matrix and you can "type" in letters by selecting them with the ROKU remote. It's less kludgy than it sounds and since it starts search with the very first letter you enter, I've generally been able to find what I want within the first couple of letters.
My only real complaint is that there is less of a selection of shows available for streaming than on DVD. NetFlix: The newest shows come first on DVD with Netflix. You have to wait for them to be available with NetFlix streaming and some are never available. But there is a good selection of "Midsomer Murders" and "Kolchak, The Night Stalker" TV programs, so I'll probably keep NetFlix as a streaming-only option.
Amazon: With AmazonPrime, the selection is limited and tends to run to older movies (either really old, or from the 70's, 80's, 90's with sporadic ones from this century). But since it's part of their "free w-day shipping" it's a nice feature since we buy a lot from Amazon. My husband likes Amazon because he got to stream/watch a few Marx brothers movies. The selection of TV shows is somewhat limited, generally just one or two episodes instead of an entire season. However, you can get new movies on a "pay-for-view" basis that lets you "rent" for two days during which you can watch it until you're sick of it. I was also able to watch some "Murdock Mysteries" TV shows, although I had to pay for them.
I briefly looked at some of the other services, e.g. HULUPlus, but I figured that paying for NetFlix and AmazonPrime was sufficient. (I warned you I was cheap, right?) At one time, I was wondering if we could shut off our satellite subscription and just go with streaming video, but there are too many things we like to watch, e.g. Weather, Fox News and O'Reilly, that are just easier via the satellite.
If you need to create an Internet access point in your house but can't drill holes to run cables and wireless doesn't work for you, I would definitely recommend looking at a PowerLine product. You don't have to use the devices I used: I only included them because they worked for me and they are good examples of how you can get streaming video for under $200.
Good luck--I'm off to watch a few episodes of the original "Star Trek"--on streaming video!