Since you are asking the question, you are probably unable to hide your IP from anyone who is really interested.
And the question is pretty much useless. Why do you think that you should hide your IP? Who do you want to hide it from? If you gave us some more details, then we could give you some useful advice.
Also, you do realise that when you are using a proxy, all your traffic goes through one server and the owners of that server can monitor, collect, alter and report anything at their will? This includes most of your online passwords, e-mail content, website content etc etc..