We make single-user use cases easy around here. See [node:124] for some overview information. When you create an application on dev.twitter.com/apps you can also generate an access token that represents your account's relationship with your application -- without having to go through the web-based OAuth flow to negotiate it.
You can then skip all those steps around acquiring request tokens and access tokens and jump right to the point where you use the combination of your API keys & secrets and the access token & secret to make signed requests to Twitter on your own behalf.
Once you have the four pieces of information you need, you can plug them easily into code such as this from tmhOAuth:
$tmhOAuth = new tmhOAuth(array(
'consumer_key' => 'YOUR_CONSUMER_KEY',
'consumer_secret' => 'YOUR_CONSUMER_SECRET',
'user_token' => 'A_USER_TOKEN',
'user_secret' => 'A_USER_SECRET',
$code = $tmhOAuth->request('GET', $tmhOAuth->url('1.1/statuses/user_timeline'), array(
'screen_name' => 'SBTDev'));
$response = $tmhOAuth->response;