ok, sorry, I really meant http://jsfiddle.net/Q3cvr/1/ instead of http://jsfiddle.net/Q3cvr/, if you want to check it out... I also updated it to http://jsfiddle.net/Q3cvr/3/ to show how adjacent spaces behave.

Therefore I really think this is the good direction.

I agree we should prevent \n for even being entered (instead of filtering after the fact). To do this, you need to add an event listener for `keypress` and do something like:
```javascript
// <ENTER> (Appears to be 13 on keyboard and 14 on VK)
if (event.keyCode === 13 || event.keyCode === event.DOM_VK_ENTER) {
  event.preventDefault();
}
```
(stolen from the more complex code in https://github.com/mozilla-b2g/gaia/blob/master/apps/sms/js/recipients.js#L962)