Passage: In 2005, Apple CEO Steve Jobs conceived an idea of using a multi-touch touchscreen to interact with a computer in a way in which he could directly type onto the display. He decided that it needed to have a triple layered touch screen, a very new and advanced technology at the time. This helped out with removing the physical keyboard and mouse, the same as a tablet computer. Jobs recruited a group of Apple engineers to investigate the idea as a side project.  When Jobs reviewed the prototype and its user interface, he conceived a second idea of implementing the technology onto a mobile phone. The whole effort was called Project Purple 2 and began in 2005.Apple created the device during a secretive and unprecedented collaboration with AT&T, formerly Cingular Wireless. The development cost of the collaboration was estimated to have been $150 million over a thirty-month period. Apple rejected the "design by committee" approach that had yielded the Motorola ROKR E1, a largely unsuccessful collaboration with Motorola. Instead, Cingular Wireless gave Apple the liberty to develop the iPhone's hardware and software in-house.The original iPhone was introduced by Steve Jobs on January 9, 2007 in a keynote address at the Macworld Conference & Expo held in Moscone West in San Francisco, California. In his address, Jobs said, "This is a day, that I have been looking forward to for two and a half years", and that "today, Apple is going to reinvent the phone." Jobs introduced the iPhone as a combination of three devices: a "widescreen iPod with touch controls"; a "revolutionary mobile phone"; and a "breakthrough Internet communicator".Six weeks before the iPhone was to be released, the plastic screen was replaced with a glass one, after Jobs was upset that the screen of the prototype he was carrying in his pocket had been scratched by his keys. The quick switch led to a bidding process for a manufacturing contractor that was won by Foxconn, which had just opened up a new wing of its Shenzhen factory complex specifically for...

Question: Jobs begin thinking of implementing a user interface into a cellphone in which year?
2005