I was thinking about doing a similar power. The trick is altering other peoples sense of time through some means which slows there perception of time down or stopped altogether, thus causing you to go faster in there mind since you are still going at a regular pace and not their perceived slower time, or if you halt their time for a short amount of time, it would appear as though you disappeared and reappeared somewhere else, though stopping someones perceptions is difficult, so it's actually be like to the extreme of the first one still causing them to think you disappeared.

Edit: I left out some details on this but it's a lot easier to describe verbally so if you have questions just call me on skype because I can get into more detail. As for speeding up time and stuff like that in perception well that still won't speed up the body, in fact you'd get frustrated at how pathetically slow your body was moving since it couldn't keep up with your mind.