I recently received a boat load of interesting articles that I'd like to read on the Subway etc on the way to work on my iPhone. I want an app that allow me to store .docx and .pdf files on my phone so I can just open them up without being connected to 3G or my computer etc (like on the Subway when there is no connection). I have noticed a couple interesting apps like Documents to Go and HardDrive but I want to make sure that I can actually store the files locally on my iPhone before I spend the money on them. Does anybody use any of these apps? Is it worth it to spend the 15 bucks on Docs to Go? I remember a 5 dollar one that looked interesting, Air Sharing I believe it was called....