[ronp]

I'm an attorney, so I have to recommend consulting with an attorney licensed to practice law where you live. Talk to her/him about drafting a simple no-compete & non-disclosure with the other two partners assigning you exclusive rights to move forward. Give them some money or other valuable consideration to make the contract binding. I would not recommend just doing nothing in the hopes that nothing bad happens; if you are wildly successful you can bet there will be repercussions.

[etm117]

I am not a lawyer, but I think this idea sounds the most reasonable. As a side effort in case they do not like the proposal as drafted, you could maybe give them 2% (or some other number) of equity in any new entity you create to run with the idea with them giving up all rights at that point. It is a small amount of equity in the "new" business and the signed contract prevents them from coming back years from now and asking each for their 33%.