Where should I look for consumers key and secret in order to register OAuth?

I'm trying to register OAuth from R in order to analyze tweets (using tw开发者_开发知识库itteR and ROAuth packages), but I don't know how to get consumers key and secret key. What should I do?

The project vignette for twitteR discusses this to some degree. It's in section 6 (page 7).

Syntax examples are even given:

> cred <- OAuthFactory$new(consumerKey = YOURKEY, consumerSecret = YOURSECRET,
+ requestURL = requestURL, accessURL = accessURL, authURL = authURL)
> cred$handshake()