When you buy an iPhone, let's say, 8Gb model, how much space do you really get ? I am trying to figure it out whether or not an 8Gb model will fit my songs, videos and PDFs and future applications out of SDK. Currently I have 4Gb of stuff altogether (by the way, I heavily use gmail. Is any email saved on the iPhone at all ? Hopefully not ) I would love to get a more expensive model but I would rather buy something that will do the work in the next two years. Thanks for the help !