Who Can Participate
Requirements for participation include the following:
A baccalaureate, bachelors, or undergraduate degree from an accredited college or university (more advanced degrees are welcome); and A curiosity about how well you make predictions about world events – and an interest in exploring techniques for improvement.
I believe the DAGGRE group is still accepting new participants.
I switched to DAGGRE from GJP, and have been happy with the decision. DAGGRE organized an interesting forecasting workshop for participants (for which they covered travel expenses), and they have indeed made good on the promised honorarium.
They use a prediction-market methodology, and Robin Hanson is among the team leads.
Previous: http://lesswrong.com/lw/6ya/link_get_paid_to_train_your_rationality/
The IARPA-run forecasting contest remains ongoing. Season 1 has largely finished up, and groups are preparing for season 2. Season 1 participants like myself get first dibs, but http://goodjudgmentproject.com/ has announced in emails they have spots open for first-time participants! I assume the other groups may have openings as well.
I personally found the tournament a source of predictions to stick on PB.com and I even did pretty well in GJP. (When I checked a few weeks ago, I was ranked 28 of 203 in my experimental group.) I haven't been paid my honorarium yet, though.