I second Roger's recommendation for using rgdal. I've been writing to and
fro from img files with few problems. The only problem I have with ArcGIS is
that the statistics have had to be recalculated in Arc for floats to get the
display to work correctly. But, Arc has a batch statistics tool that doesn't
crash often (when a tool works reliably in Arc I'm surprised and pleased
beyond reason). Keep up the good work Roger, Tim, Edzer and all the
rest. -Andy