Geez, Google really wants you to install its toolbar, right? They usually introduce new web features, like their goo.gl URL shortener, into it first, leaving developers to figure out non-toolbar executions. Luckily, a web app and Chrome extension are on it.
Digital Inspiration points us toward both a web app that spits out a goo.gl URL in one click, after pasting in a full URL first (don't forget the http:// bit, or you'll get an empty result). If that's a bit too much work for tossed-off links and you're a Chrome user, you can install the goo.gl shortener extension and do your link shortening with a toolbar button.
The appeal of goo.gl-shortened links is their theoretical longevity, but, at the moment, they lack the statistics and tracking that makes the de facto standard, bit.ly, widely appealing. We'll see what improvements come along, but for now, you can grab Google's server re-direction benefits without having to keep their toolbar installed.