At least two bookmaker webs, both located in Ireland, have active betting on the next US Presidential election: http:\\tradesports.com and http:\\www.paddypower.com. Both have odds on likely nominees. Paddy Power shows Hilary Clinton as the favorite for the White House, Rudolph Giuliani second. Tradesports has John McCain leading for the Republican nomination, Hillary Clinton for the Democratic nomination. For the election, the Democratic Party is slightly ahead of the Republican Party.
Long Bets (http://www.longbets.org) involves money, but your winnings go to a charity you select. A quick look shows a prediction for 148 years ahead; most are shorter. Making a prediction requires having a theory behind your prediction, and paying a fee. Betting is always at even odds.
Ideosphere (http://ideosphere.com) doesn't involve real money. It was designed by an intelligent libertarian, and therefore has only a minimum of restrictions on what claim you can make. (You need to find a judge for the claim, and need to state it so that it can be judged. "There will be angels blocking traffic in Los Angeles in September of 2015" would qualify, though it might not attract much interest. "A heavenly host will descend on an American city" would not.)