[R-sig-Geo] combine function in R?

[Jordan Chamberlin]

Hello list,

Is there something like a combine function in R? I'm thinking of the 
COMBINE function in the old ArcInfo (which gives a grid of unique 
cell-wise combinations of integer values in a set of input grids). There 
must be something like that already written for R, but I'm new to this, 
so I'm grateful for pointers in the right direction.

Jordan