position of first and last axis tick

how can i set the position of the first and last tick to the
borderline of a plot?

The plot should look like this one made in Gnuplot [1].
Gnu-R adds some space between the ticks and the end of plot.

do you mean like this?

plot(rnorm(25),rnorm(25), xaxs ="i", yaxs="i", xlim=c(-2,2),  
ylim=c(-2,2))

[1] http://commons.wikimedia.org/wiki/File:Atmospheric_radiocarbon_1954-1993.svg