[R-sig-Geo] Which are the most suitable, elegant or efficient packages for geographical maps in R? Which did you use yourself?

[Markus Jenning]

Hi everyone.

I remember some very interesting and professional-looking R projects that  
somehow involved geographical maps.
Now that I'd like to work with maps myself, let me ask you this question:
Which of the packages that are currently available would you think are the  
most elegant and useful for an R project that use maps?
Which packages (other than the "maps" package) did you use in your own  
projects and why?
Are there any packages that are not available on CRAN (or in some way hard  
to find) but that still deserve recognition?

Thanks for your help, and feel free to redirect me to a more suitable  
thread or even another group if you feel that this question could better  
be asked elsewhere.

Cheers,
Markus