### The following is very helpful #########
listOfFiles <- list.files(pattern= ".txt")
d <- do.call(rbind, lapply(listOfFiles, read.table))
###############################
but what if each file contains information corresponding to a different
subject and I need to be able to tell where each row came from? i.e.: I
need a new row that repeats the original filename for each observation of
the former respective files.
Any ideas?