Read ePub books WITHOUT iTune sync and iBooks

I don't have problem with iBooks.  In fact I like it as a decent ebook reader.  But I hate the fact that I have first put my ePub book in iTune at home first, and then sync them to my iPad.  I want to be able to add ePub books whenever I want.  Luckily, ReaddleDocs does exactly that.  I just need to add those ePub book files in ReaddleDoc folder through iTune, and I then I can launch the ebook reader built into the app.  Nice.