JPP and OOS are probably the most useful new tools for SketchUp since version 6 was released. And one can wonder if SketchUp 7's tool set will be able to match these incredibly useful tools. We can only wait and see. Both JPP and OOS are free scripts and are available here and here respectively.

SketchyFFD (Free Form Deformation)

We saved the best for last! FFD has the power to deform an existing mesh, yet keep the integrity of the entire base mesh into account. This basically means that whatever you deform - within reasonable limits - will bend organically along the path input by the user.