One of my powerline adaptors failed recently and I thought I would have to buy another. Fortunately I was able to use an old router running dd-wrt linux to act as a wireless bridge. (A wireless bridge joins standard network sockets to the wireless network so that you can use wired networking devices anywhere you can receive a wireless signal e.g. to connect an Xbox 360).
You need a router that is capable of running dd-wrt, (you can check your router on their website) mine is a Buffalo WHR-HP-G54 . You will need to install dd-wrt on your website – this is as simple as updating the router firmware
Next you need to connect your router to your pc with a cable and follow the instructions on the dd-wrt wiki.
When this is complete you have four network sockets that can be positioned anywhere that you receive a wireless signal. I have two wired IP cameras connected to mine – and I saved the cost of buying new hardware!