I know some of you have been involved with Bitcoin in the past, so maybe this will be of interest for you.
There is a newer crypto currency on the scene called Ethereum, and it is currently very profitable to mine on graphics cards and it's also the second largest crypto-currency by market cap.
Official Site -
https://www.ethereum.org/Wiki Page -
https://en.wikipedia.org/wiki/EthereumMicrosoft like it -
http://www.coindesk.com/microsoft-ethereum-3-million-developers/Mining Guide -
https://www.cryptocompare.com/mining/guides/how-to-mine-ethereum/Although I initially followed this mining guide, I now mine for a pool rather than solo mine. The pool is here -
http://eth.nanopool.org/ There is sufficient help on there on how to mine for the pool.
I've been mining it for 5 weeks now. For the first two weeks of mining I used a couple of Radeon 7950s. I set my payment address to my account on
https://poloniex.com/ and mined directly to it, selling every day whatever I mined. In two weeks that netted me 0.48 BTC, around £140. Electricity cost is naturally a fraction of this.
I've since added two more Radeon 290x and a Radeon 7970 and for the last three weeks I set my payment address to my account at
https://www.bitfinex.com/ where there is now a ETHUSD market. Everyday I sell what I mine directly for USD. After three weeks I now have over $400 in my account there.
Essentially, in 5 weeks I've mined around £400, even with the first two weeks only being with 2 graphics cards. Note: 2 x 7950s gave me about 45mh/s. I now get 127mh/s across all 5 cards.
As you can see, this is very worthwhile whether you already have the equipment or not. Hopefully there are enough links here to help anyone out that fancies giving it a go.
Good luck.