<p>How can I load an external JavaScript file using a bookmarklet?  This would overcome the URL length limitations of IE and generally keep things cleaner.</p>

2015 Update
Content security policy
will prevent this from working in many sites now. For example, the code below won't work on Facebook.
2008 answer
Use a bookmarklet that creates a script tag which includes your external JS.
As a sample:
```
```
javascript:(function(){document.body.appendChild(document.createElement('script')).src='** your external file URL here **';})();
```
```