I've seen links using it, but I can't find my way around on how to use it.
The page [1] says:
Google URL Shortener is currently available for Google products and not for broader consumer use.
What Google products are they talking about? How can I use it?
EDIT
Well, goo.gl is now public!
It is public as of today.
Just goto http://goo.gl and it should be self explanatory from there.
Add .qr to get a QR Code for the link
Add .info to get statistics for that link
goo.gl/v4vg
goo.gl/v4vg.qr
goo.gl/v4vg.info
The only one I'm aware of is the Chrome extension for goo.gl URL Shortening [1].
[1] https://chrome.google.com/extensions/detail/iblijlcdoidgdpfknkckljiocdbnlagkYou can definitely use it with the goo.gl URL Shortener Chrome Extension [1].
Here's this page shortened, as evidence:
In addition, quoting the Official Google Blog [2] (December 2009):
[1] https://chrome.google.com/extensions/detail/iblijlcdoidgdpfknkckljiocdbnlagkGoogle URL shortener is not a stand-alone service; you can't use it to shorten links directly. Currently, Google URL Shortener is only available from the Google Toolbar and FeedBurner. If the service proves useful, we may eventually make it available for a wider audience in the future.
There is a Firefox add-on. Goo.gl lite [1]
[1] https://addons.mozilla.org/en-US/firefox/addon/55308/Since Feedburner is using it when it posts to Twitter for me, I also like to use it when I post a link in Twitter directly. In addition to the Chrome extension, there is a bookmarklet for getting a goo.gl URL that works well:
javascript:window.googl_callback%20=%20function(response){if(response.error_message){alert("An%20error%20occured:%20"%20+%20response.error_message);}else{alert(response.short_url);}};%20var%20s%20=%20document.createElement("script");%20s.src%20=%20"http://ggl-shortener.appspot.com/?url="%20+%20encodeURIComponent(window.location.href)%20+%20"&jsonp=googl_callback";%20void(document.body.appendChild(s));
Update: As noted in Chris' answer [1], the goo.gl service now has a web front-end for all to use.
[1] http://webapps.stackexchange.com/questions/311/how-can-i-use-the-goo-gl-shortener-service/7265#7265They are talking about Feedburner for example, which sortens URLs with goo.gl when it posts to Twitter.
There's also a Safari 5 extension here [1]. Alternatively, this extension [2] will shorten to youtu.be, flic.kr, or goo.gl depending on the website you're trying to shorten.
[1] http://code.google.com/p/safari-googl-shortener/Shareaholic for Google Chrome [1] creates goo.gl short links too.
[1] https://chrome.google.com/extensions/detail/kbmipnjdeifmobkhgogdnomkihhgojepI think its just internal to Google at the moment. I think you will need to wait a little while