The sonic screwdriver

They sort of ruined it's utility in the new show now that I think back on it. It was a good plot device but it seem rather convenient for them to completely ignore it, excusing it's uselessness by pretending it was out of date with modern technology. The sonic screwdriver could open up doors on spaceships in the future. If it couldn't open something or make something work it was because the Doctor hadn't fiddled with it enough yet. They largely disposed of use of psychic paper as well I noticed.