Your bash/zsh history in the cloud
shellsink is a searchable, tagable, and awesomely web accessible version of your bash history. by installing the client all commands issued in bash are stored in the cloud ready to be accessed by you from any other command line or web browser anywhere.
If you've ever wasted time trying to remember a particular command line incantation, shell_sink is for you. It stores commands and makes them easily accessible with searching and tagging. If you work on multiple computers shell_sink can aggregate your history across all machines. System administrators can even use it to aggregate commands issued across an entire organization making them fully searchable. Never lose a command again.
It is worth noting that I stopped paying the hosting bill of the google app engine app in 2010, so the public free for all of bash history that was shell-sink.com is no longer there. Sorry! Since then there have been no updates to the app, but I still think it is a great idea. I'd love to collaborate with anyone who wants to give the project some love.