Lance already mentioned this, but I wanted to expand upon it. Community Wiki answers are the best way to collaborate on a solution, as explained in this blog post:
The intent of community wiki in answers is to help share the burden of solving a question. An incomplete “seed” answer is a stepping stone to a complete solution with help from others; an incomplete question is a hindrance and an obstacle to getting a solution as no one understands the inquiry. It is in answers that the goal of community wiki, for the community, by the community, shows its truest colors.
Yet even in answers, true collaboration is scarce. Most of the time, a single individual can provide a complete answer. There are even times where a question looks like it’ll need a massive effort, but one gallant user steps up to the plate with an impressive and comprehensive answer.
Note, however, that Community Wiki should usually be used sparingly.
Most of the time, you should be asking yourself "How can I improve this post so that community wiki isn’t needed?" Community wiki is like a cheese knife: it is a specialized tool to be used sparingly.
Community wiki is for that rare gem of a post that needs true community collaboration. That’s when community wiki shines. If your site is teeming with community wiki posts — particularly in questions — you should consider the above points carefully.
In other words, you can use Community Wiki answers in those rare cases where the contributions of more than one person are needed to adequately address a question. However, if you want to ask a question that is open-ended and hypothetical or for which every answer is equally valid—as explained in the FAQ—I'm afraid that Stack Overflow isn't the right place to do so.