If tomorrow you wake up anywhere between 500 and 2000 years in the past, what would you do to get a message across time to inform friends or families of what happened?

Feel free to choose at which point in time, 500–2000 years ago, you ended up waking up. Adapting on your new present reality, how do you think you could go about making sure that down through the ages, a sign or a message or maybe something else entirely would clearly reveal to present day friends or families that the reason for your mysterious disappearance in 2011 was that you travelled back in time for reasons unknown even to you?

Would you for example, try to be a successful business owner and name that company, Fluther? Would you have letters in bank vaults with instructions of being released at certain dates in the future?

Would you send a letter to yourself? Sorry this could be confusing I know but I’m mainly interested in how one might go about creating enough presence in the past in order to deliver a message to the future rather effectively. Thanks.