Also not a trick but here are some resources/examples I have collected
An example of plotting small multiple maps of Areal data in R using the lattice package.
There are a few questions on StackOverflow asking about mapping and R, and here is one with a nice example. I would look at the other answers and the resources they give (as well as search for some more examples) on SO as well.
A different link to the same r-sig-geo group Brad already gave. It is very active, and Roger Bivand answers questions practically every day on the group. Both related to programming and statistical analysis.
Besides checking out the cran spatial page I would also suggest specifically checking out the Spatstat page maintained by Adrian Baddeley. Plenty of examples, a course, and a forthcoming e-book. (At the moment I have been going through the spatstat course, and I think it is a much gentler introduction than the Bivand book).
Not a free resource, but for anyone interested in R I would suggest you check out the Use R! series by Springer. The have a book Applied Spatial Data Analysis with R directly pertinent (also the book A Beginner's Guide to R is my suggested learning R book.)
A free e-book, A Practical Guide to Geostatistical Mapping (Hengl 2009), has examples of applied geostats in R, GRASS, and Google Earth (KML).
If I find anymore good examples I will continue to update (I hope other people post good examples as well!)