<p>I've got several developers about to start working on the front end of a jquery-based web application. How can we structure the application so that multiple developers can work on the ui at the same time. The end result for the user will just be one web "page", but I don't all of the client development to occur in one file. There is already another team working on the back end.</p>

If you're starting completely from scratch, you could break it up into the standard 3 tier architecture.
Have one person working on the database structure and creating the appropriate access libraries to the data.
Have one person working on the business/workflow tier, setting up all the interaction of data.
Have the third person doing all of the front end work with jQuery.
I'm sure following this there would be minimal collision, and each could work with some mock data/methods until the official stuff comes online.