A "Whoever I wanna be" mask like Kaitou Kid! XD XD XD
Or perhaps, roller shoes! Press one button to kick, press the other to roll!
Or perhaps something that lets him fly temporarily, like Astroboy, A shoe with an engine! XD
Hmmm... Or perhaps a net that shoots out from erm... his belt, to catch the culprit?
Or something that makes Conan taller? XDXDXD