Meguiar's has three new products out for 2009, all of which make use of very specialized abrasives technology trickled down from their high end professional products. These products are just now arriving on store shelves and should be available at most larger auto parts stores as well as Wal-Mart and Target.
In order of aggressiveness, from least to most:
SwirlX
ScratchX 2.0
Ultimate Compound
All three are highly effective when used by hand, but still require some elbow grease. Those of you familiar with ScratchX will recognize the name only - the new 2.0 version is a totally different animal. The abrasives used are micro fine, extremely hard, and incredibly uniform in size and shape. This gives them the ability to not only cut relatively quickly but also impart a very high degree of clarity to the finish.
It is recommended to use a soft foam wax applicator pad and avoid terry cloth. Terry cloth has some bite and since any of these products need to be applied with some elbow grease terry cloth has a high potential for marring the surface. As the paint color gets darker this becomes more and more critical.
Disclaimer: yes, I work for Meguiar's