How to make an API call using meteor

You are defining your checkTwitter Meteor.method inside a client-scoped block. Because you cannot call cross domain from the client (unless using jsonp), you have to put this block in a Meteor.isServer block.

As an aside, per the documentation, the client side Meteor.method of your checkTwitter function is merely a stub of a server-side method. You’ll want to check out the docs for a full explanation of how server-side and client-side Meteor.methods work together.

Here is a working example of the http call:

if (Meteor.isServer) {
    Meteor.methods({
        checkTwitter: function () {
            this.unblock();
            return Meteor.http.call("GET", "http://search.twitter.com/search.json?q=perkytweets");
        }
    });
}

//invoke the server method
if (Meteor.isClient) {
    Meteor.call("checkTwitter", function(error, results) {
        console.log(results.content); //results.data should be a JSON object
    });
}