Dom Sagolla is one of the creators of the micro-blogging service Twitter, and author of 140 Characters: A Style Guide for the Short Form.
Dom's iPhone application development company DollarApp operates on an intriguing principle - using one person to create a new product in one month - and selling it for one dollar.
Key advice
"The simpler you make your idea, the easier it is... to understand the market and get it out there".
