Simple example of using 2-legged OAuth in Node.js (requires node-oauth)

index.js

var express = require('express');
var oauth   = require('oauth');
var sys     = require('sys');
var app     = express.createServer();
var key     = "[api-key]";
var secret  = "[api-secret]";
var request = new oauth.OAuth(null, null, key, secret, '1.0', null, 'HMAC-SHA1');

app.get('/api-request', function(req, res){
    request.get(
        "http://127.0.0.1:8000/api/1.0/data.json",
        null,
        null,
        function (err, data, result) {
            if (err) {
                res.send("Error getting data : " + sys.inspect(err), 500);
            } else {
                res.send(data)
            }
    });
});

app.listen(parseInt(process.env.PORT || 88));

package.json

{
  "name": "node_oauth",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "express": "^2.5.10",
    "oauth": "^0.9.14",
    "sys": "0.0.1"
  }
}

Added stuff to make sure it all works with the latest node as of this writing (v5.0.0)