plotting multiple ggplots in one window

gistfile1.txt

library(grid)

plot1 <- ggplot(data.frame(x=1:10, y=1:10), aes(x=x, y=y)) + geom_point()
plot2 <- plot1
plot3 <- plot1


nrow <- 1
ncol <- 3
vp <- viewport(layout=grid.layout(nrow, ncol))

grid.newpage()
pushViewport(vp)

print(plot1, vp=viewport(layout.pos.row=1, layout.pos.col=1))
print(plot1, vp=viewport(layout.pos.row=1, layout.pos.col=2))
print(plot1, vp=viewport(layout.pos.row=1, layout.pos.col=3))