Does anyone else use Tor? It's an Onion Router that bounces your traffic, encrypted, through three relays, to privatize your data. In essence, you're behind three proxies. It's a lot better than any paid proxy service out there. It uses a modified version of Firefox with a button to change IP's instantly. If you like using a shell, it's even got a CLI. Tor is open source too, meaning free and you know there aren't any backdoors. It has way more IP's than things like Hide-My-IP because it's made up of thousands of volunteers around the globe.
https://www.torproject.org
https://www.torproject.org