[R] bottom legends in ggplot2 ?

[Avram Aelony]

Has anyone had success with producing legends to a qplot graph such that the legend is placed on the bottom, under the abcissa rather than to the right hand side ?

The following doesn't move the legend:
       library(ggplot2)
       qplot(mpg, wt, data=mtcars, colour=cyl, gpar(legend.position="bottom") )


I am using ggplot2_0.8.2.

Thanks in advance,

Avram