Source: http://lifehacker.com/block-ads-on-all-your-devices-with-a-raspberry-pi-1325298085
Ads can be one of the internet's more annoying things, and there are few things worse than watching a flash animation for deodorant suck up all your bandwidth. While you have plenty of software solutions to block ads, you can also do it on a deeper level with a Raspberry Pi.
This projects turns your Raspberry Pi into a wireless access point, then installs software that makes ads time out. Then, you route your traffic through the Raspberry Pi and that blocks ads on all your devices, from your tablet to your game console. Head over to Adafruit for the full guide.
Raspberry Pi as an Ad Blocking Access Point | Adafruit