Maplin electronics sell a network cable tester, they used to have one at £20 or so, but the current ones listed on their website cost £59+ ouch!
However when I was network cabling, I used to plug my laptop into the point and check for a link and/or connect to the internet - google always provides a prompt response.
Using a little sideways logic ( I'm clever at that) how about plugging a cheap hub into the network socket and see if the "green" active light starts to flash.
That has just accured to me as I have just networked two PC's in one room at work today that are connected to a larger network. I was able to quickly see with three flashing lights (on the hub) that the 2 PC's were linked to the larger network.
Regards and good fortune with the networking.