Don't worry about the weight. I currently have an E61 (yep why I want an upgrade!!) and it is about the same thickness and if about the same weight if not lighter. I've had the thing sat in my suit internal pocket and jeans back pocket inside a case for the past 4 years so I have no qualms about space for the N900. It's not actually that much thicker than the new iPhone either, just that the iPhone is curved on the back to make the edges look thinner!