Revving Chrome for a Cause

Google's launched this great initiative/Chrome extension called "Chrome for a Cause," where for every tab opened (up to 250 tabs/day) Google will contribute towards charity. You can download the extension here:

http://www.google.com/chrome/intl/en/p/cause/

Now let's say you're in the mood to speedily log 250 tabs open, but your Ctrl+T muscles are sore. Several code solutions have popped up, including a full-on Chrome extension which automates the process.

My question: why can't this run in Javascript?

My response: Chrome for a Cause Fastest bookmarklet

Here's the code:
javascript:i=260;function addTab(){if(--i==0){clearInterval(j)}x=window.open('');x.close()}j=setInterval('addTab()',1000);void(0);

Just let it run for ~5 minutes, and you're done. You've helped provide a year's supply of clean drinking water for someone on earth.