function(jj.col.names, jj.modes, nrows, ncopies)
{
	mem.tally.reset()
	# build up data.frame expression
	jj.express <- "jj.df<-data.frame("
	jj.l <- length(jj.modes)
	# add first col
	jj.express <- paste(jj.express, jj.modes[1], "(", nrows, ")", sep = "")
	# loop through rest
	for(i in 2:jj.l) {
		jj.express <- paste(jj.express, ",", jj.modes[i], "(", nrows, ")", sep = "")
	}
	jj.express <- paste(jj.express, ")", sep = "")
	eval(parse(text = jj.express))
	dimnames(jj.df)[[2]] <- jj.col.names
	jj.big.df <- jj.df
	if(ncopies >= 2) {
		for(j in 2:ncopies) {
			jj.big.df <- rbind(jj.big.df, jj.df)
		}
	}
	print(mem.tally.report()/1000000.)
	print(object.size(jj.big.df)/1000000.)
	return(jj.big.df)
}