crconsole
crconsole is a remote Javascript console for Chrome/Webkit that runs in your terminal:

Install
With node.js and the npm package manager:
npm install crconsole -g
You can now use crconsole from the command line.
Connecting
Start chrome with remote protocol enabled:
google-chrome --remote-debugging-port=9222
$> crconsole
google.com> 1+1
2
Commands
There are two extra REPL commands available beyond the standard node.js commands. .tabs lists the open tabs. .switch 2 switches to evaluating in a tab. The argument is the index of the tab to switch to.
See also
Credits
Parts of the code taken from fxconsole. Uses chrome-remote-interface to communicate with Chrome.