cloud-to-butt
Chrome extension that replaces occurrences of 'the cloud' with 'my butt'
Note that there are forks of this extension that simply replace 'cloud' with 'butt'. In my personal opinion, that approach is too broad and it's less funny as a result, but it is clearly a very polarizing issue in the cloud-to-butt user community. Forks are free to do whatever they like. But officially, this extension replaces only the phrase described above. Thank you for your concern.
Screenshot Gallery
http://www.flickr.com/groups/cloud-to-butt/
Installation
In Chrome, choose Window > Extensions. Drag CloudToButt.crx into the page that appears.
Safari Version
Can be found here: https://github.com/logancollins/cloud-to-butt-safari
Firefox Version
Can be found here: https://github.com/DaveRandom/cloud-to-butt-mozilla
Opera Version
Can be found here: https://github.com/DaveRandom/cloud-to-butt-opera