Slacker is on a roll today. Not only have they signed with all four major music labels (effectively giving them a far deeper playlist), but now they've gone and inked deals with indie music IODA, The Orchard, Beggars Group and Matador Records, IRIS, Ubiquity Records and Sanctuary Group PLC.

The agreements give Slacker the rights to play their "personal radio stations" anyway - from the online Web player, to the Desktop player, as well as on their upcoming Slacker Portables.

It looks like Slacker is really pushing the "discovery" aspect of their service (IODA's catalog includes close to 1 million tracks alone), and it looks like the flood gates have just been opened.

Now, if they could only get that Portable on the streets....

Slacker, the Internet Radio/Satellite Radio hybrid service, has finalized agreements with the major labels EMI Music, Universal Music Group and Warner Music Group - making the labels' content available to listeners on the Slacker Personal Radio service.

Sony BMG Music had already previously reached a similar agreement with Slacker. The addition of EMI, UMG, and Warner gives Slacker agreements with all four major record labels.

With all four music labels under its belt, Slacker listeners will now have access to a much deeper playlist to access on their personalized radio stations. And as part of the agreement, Slacker listeners can transfer their personalized stations to Slacker Portable Players with a single click and automatically refresh them via Wi-Fi or over USB.

The Slacker Portable Player is still "coming soon," but I assume they wanted to reach this agreement first before launching their retail offering. Slacker Personal Radio is available for free (for both online use and on the Slacker Portables) using an ad-supported model (the premium service will be unveiled soon).

Also "coming soon" is the Slacker Satellite Car Kit, which delivers fresh content to your Slacker Portable Player directly to your car via satellite. Complete with a car dock and antenna, the Satellite Car Kit allows you to receive new music for your stations while you drive. The Slacker Portable Player will store content in its cache, so your music never stops playing even when you lose signal.