Idea for a multi-faceted reality/TV/computer game

It's like a net game but with a reality dimension: a network game for the non-sedentary. You get directions by e-mail or mobile phone, run five miles here, buy a trinket there, find the secret clue here. Your progress is monitored on the network portion of the game. Particularly successful or charismatic players are filmed and their activity is shown on the TV portion of the game. Some people (people who are rich or don't have very big living expenses) quit their jobs and devote themselves full time to playing. Some people might actually be paid to play the game because they are interesting or charismatic.