Lattice is an implementation of Trellis Graphics for R. Its interface
  is based on the implementation in S-Plus, although there are several
  differences. Existing Trellis code written for S-Plus should
  ideally work unchanged (or with minimal change) in Lattice. One
  exception to this is when custom panel functions are used. See the
  entry for panel in help(xyplot) for help with this aspect.
  As of now, most high level Trellis functions in S-Plus have been
  implemented, although the 3d display functions (notably
  wireframe and contourplot) are often buggy and
  inefficient.
  Lattice is built upon the Grid Graphics engine for R being developed
  by Paul Murrell and requires the grid add-on package.
  Type library(help = lattice) to see a list of (public)
  Lattice graphics functions for which further documentation is
  available. Apart from the documentation accompanying this package, 
  several documents outlining the use of Trellis graphics is available
  from Bell Lab's website that might provide a holistic introduction to
  the Trellis paradigm. Lattice also has a website with some tips.
Cleveland, W.S. (1993) Visualizing Data.
Becker, R.A., Cleveland, W.S. and Shyu, M. ``The Visual Design and Control of Trellis Display'', Journal of Computational and Graphical Statistics
  Lattice Webpage:
  
xyplot.  To learn how to customise the Graphical parameters used by the Lattice
  functions, see lattice.theme and lset.
  To learn how to initialise new devices or change the settings of the
  current device, see trellis.device
  To learn about sophisticated (non-default) printing capabilities, see
  print.trellis. 
Here is a list of `high level' functions in the Lattice library with a brief description of what they do:
Univariate:
  barchart bar plots
  bwplot box and whisker plots
  densityplot kernel density plots  
  dotplot dot plots
  histogram histograms
  qqmath quantile plots against mathematical distributions
  stripplot 1-dimensional scatterplot
Bivariate:
  qq q-q plot for comparing two distributions
  
  xyplot scatter plot (and possibly a lot more)
Trivariate:
  levelplot level plots (image plots in R)
  
  Hypervariate:
  
  splom scatterplot matrix
  
  parallel parallel coordinate plots
  
  Miscellaneous:
  rfs residual and fitted value plot (also see
  oneway)
  See llines if you need to write/port nontrivial panel
  functions.