Files lite is pretty cool for 2 reasons, first you can get files off the phone using a simple web browser and upload files by setting up a creating a network place (on Windows at least, Macs have other instructions… which are here. :) The fact that I can load up the iPhone with a bunch of files, and then let anyone access it via a simple html call is pretty darn sweet. Most likely use case? You can carry your latest deck (powerpoints for you non tech valley people), or pics, or songs.
The second thing I like? I love the simplicity, yet really nice UI on the iPhone. Now agreed there is not much there, but it has that attention to detail (font, color, etc) that you come to expect with Apple inspired products.
Now, that being said, I really wish I could get access TO my pics or sounds. Since this is just 1.1, I would bet this will be available in the near future. Now, if you need something a bit more feature rich, I would recommend you have a look at either TouchCopy or use WinSCP and SSH.