Now that I am trying to use our NAS for backups and to keep our content. I tried both 802.11g wireless and powerline networking to connect the Mac mini and the NAS. Unforunately, I never got more than 5Mbs for sustained transfer rate. I decided that running ethernet around the house is the best way to get a high sustained transfer rate.
The builder of our house did some strange things with the structured wiring. They installed 3 RG6 cables to every room (so you can have both satellite and cable), but they only installed one Cat5e to every phone jack. I know that it is not ideal, but I decide to run ethernet on two of the pairs of the Cat5 cable, while the phone line uses one.
The current plates use Quick Port connectiors for the jacks, so I bought Cat5 jacks for the places that I want ethernet drops, and new plates to fit the addtional jack. I also bought a couple of Cat5 expansion boards to put at the distribution point.
Installing the jacks went very well, but when I went to splice in the expansion boards, I saw that all of the drops were essentially daisy-chained together. I then bought and installed a couple of bridging modules, and rewired all of the phone line drops. Now each of the drops are punched down to the these modules, so it is easy to change each room's drops without much trouble.
Once made these changes, I am able to get sustained 40Mbs data transfer rate between the Mac mini and the NAS.
Update: Tonight, I was able to get 80Mbs between the macBook Pro and he Mac mini.