I'd be willing to escrow this, provided we agree on some rules:

1) Lower limit of BTC0.001 and upper limit of BTC1000 (i.e. a user could double their BTC0.001 or double their BTC1000)
2) Doubling of BTC must occur within 5 days (120 hours) of starting.
3) The guide specifically cannot mention reselling the information in the guide itself, or any other "get rich quick" guide.
4) All users who accept your bet must double their chosen amount of BTC in the time period mentioned above.
5) If any user fails to double their BTC, while faithfully following the guide, the bet is lost.

Sound fair?