I like Prepopulate. I like to have that pseudo-RESTful way of preloading a form to minimize the amount of work a user has to do to get to the point of submitting a form. But I also like clean URLs. This post reviews in detail a technique to use a single prepopulated nodereference field to prepopulate a bunch of other fields based on that reference.
Bio in Brief: I spend a lot of time thinking about how to build collaboration tools in Drupal. Before that I noodled about with Java looking at long-term data preservation and geospatial data discovery.