Jame,
Simply put; Anything you as the GM want or need it to be.
The first DGP 'Four Knight' adventure had an example. A Zho spy could change computer memories via some sort of extremely rare psionic ability. The Consulate found him, trained him, and managed to insert him aboard am x-boat tender where he could 'queer' selected bits in the terabytes of message traffic he handled.
When creating a 'special' talent all you really need do is keep an eye towards game balance. You don't want something too powerful, useful, easy, etc. that will take over your campaign.
Sincerely,
Larsaen