there are so many chase missions in the first 3 memory blocks you will eventually get it during one of them twice as fast if you keep getting pick pocketed ...bastards they almost make me miss the beggars ....not really
Another good place to get this is near where you get the High Dive achievement. It's a pretty open area so you won't bump into people. Also you go there early in the game so its an achievement you can get very quickly.
this one is exactly how it sounds. you don't have to sprint for 100 meters continuously so just keep hoping around on those roofs and you'll get it in no time
