How to Invite ALL Facebook Friends to a Group, Event or Page - pretty handy

I set up a couple of groups on Facebook and wanted to invite all my
friends, but it would have taken an eternity because for some strange
reason Facebook doesn’t allow you to “select all” friends when sending
an invite. I mean, they’ll let you do it… but only if you click one at
a time! Uugh.

Well anyway I went on a little search and found that you could cheat
the system by inserting a little javascript to make it happen! Here is
how to do it:

1. Go to your Event, Group or page and click “Invite People”.
2. Once the page has loaded you should see all of your friends, but they are not selected.
3. At this point, copy and paste the javascript code below into your Web browser’s address bar, then hit “Enter”.
4. If all goes well, it selects all of your friends!

javascript:elms=document.getElementById('friends').getElementsByTagName('li');for(var
fid in elms){if(typeof elms[fid] === 'object'){fs.click(elms[fid]);}}

Thanks to Hakon for originally sharing this tip. It was a lifesaver!

How to Invite ALL Facebook Friends to a Group, Event or Page - One Man's Blog