One of my favorite Firefox extensions is download them all, you visit a web page that has mp3s on it and in one click, you can download all of them.

But that requires a bunch of additional steps. I have to then add the files to itunes and doubletwist libraries and then synch with my iPod and google phone.

Our friend Dan Kantor, creator of the awesome Streampad service that powers fredwilson.fm has come up with an even better idea; create a library in your browser and autofill it with the songs you come across on the web. The service is called Extension.fm and it is only available for Chrome right now and is invite only (but I’ve got 50 invites).

Here’s a video that shows how it works:

My favorite feature of Extension.fm is it allows you to play the last fifty songs in your tumblr dashboard as a playlist. That is something I’ve wanted to do for at least a couple years now. I’m doing it right now as I write this post. A total game changer for me. Thanks for doing that Dan!

If you want an invite, leave a comment and a way to reach you, email, twitter, etc. The first fifty requests in the comments gets an invite. No direct emails please because I need a way to calculate the first fifty so we have to keep all the requests in one channel.

I hope you like Extension.fm as much as I do.