Writer's Block: Invention

"If you could invent one thing and make it a reality, what would it be? Why?"

A real sonic screwdriver, exactly like the one Doctor Who uses. I don't need to explain. Either that or a GUI based data system like GE's financial service system for Bally and other `green screen' systems that automatically sets up the club membership number when a person dials in, like they do at Visa, and allows you to do operations without keywords and green screens, except in the case of server crashes.