FREEBITCO faucet site has started with a browser based mining service for its users. It is a great oppurtunity for those of us who always wanted to experience mining like the old days.
This new way of "faucet mining" is quite new but faucet users seem to love it. I don´t have much knowledge about the technical aspect of this system, but it works same way as minergate does. You get the choose the percentage of CPU usage as well as the total threads and start mining. As long as the browser tab is open, your computer will continuously solve hash and earn you some small amount of satoshi.
It is also possible to mine with your mobile phone. I have tried it with my iphone last night, and it actually worked.
P.s; This is not a profitable way of mining Bitcoin. It is for fun.