Slacker Radio for Android is a mobile streaming radio application similar to Pandora, but with an interesting feature not seen before in a streaming radio service. I?ve been a fan of Pandora for forever, it seems like. It might be my favorite blend of music and technology since the Minidisc. Yet, when I heard about Slacker, I was intrigued to see what this new app was offering. I?m glad I did, and I haven?t had a reason to go back yet. First off, Slacker?s music library is four times larger than Pandora. That alone makes signing up for the free account a must. But the real game changer is a new feature called caching. Caching is the big deal that gives Slacker an edge over Pandora. Once you?ve created some stations (pretty much the same way you do it on Pandora), you have the ability to cache them. What does this do? Slacker downloads and saves the data stream for your station, allowing you to listen without being online. This means you can listen to Slacker while in the subway, a submarine, or an expedition on Mt. Everest. It also means you can use wifi to cache a station relatively quickly, and then turn off 3G while you?re listening. This is better for battery life, and a good way to avoid using up data if your plan isn?t unlimited (seems to be a popular option with AT&T lately). As far as user interface and features, it?s almost identical to Pandora, and just as satisfying. Caching is available for a two week trial on the free account. $3.99/Month gets you the pro account. You?re not just paying for the cache feature: the pro account also comes with unlimited song skips, ad-free listening, mobile station caching, complete song lyrics and more.