Can I tell the R plyr package to work in parallel by default?

library(Defaults)
setDefaults(llply, .parallel=TRUE)

You'd have to setDefaults on every function for which you want to change the default formals. You can put this in your .Rprofile if you like.

You can also mess with the formals directly. e.g. formals(llply)$.parallel <- TRUE should work.