R graphics: margins are way to large

For me R has a very nice and powerfull capabilities for graphics (for example see this gallery). However, I dislike the default setting for margins and placement of axis numbers and labels. Since I always forget the setting of parameters I prefer I am adding this post. For example:

library(package="MASS")
Sigma <- matrix(c(10, 10, 10, 20), nrow=2)
mu <- c(100, 100)
tmp <- mvrnorm(n=200, mu=mu, Sigma=Sigma, empirical=TRUE)
plot(tmp, xlab="X variable (unit)", ylab="Y variable (unit)") 

Now compare this plot to the version I prefer much more:

par(bty="l", pty="m", mar=c(3, 3, 1, 1), mgp=c(1.75, 0.75, 0))
plot(tmp, xlab="X variable (unit)", ylab="Y variable (unit)")