library(ggplot2)
library(reshape2)
library(plotly)

Simple:

p <- ggplot(cars) +
  geom_point(aes(speed, dist))

ggplot:

p

via plotly:

ggplotly(p)

Volcano:

x <- melt(volcano)
p <- ggplot(x,aes(Var1, Var2)) +
  geom_contour(aes(z = value))

ggplot:

p

Via plotly:

ggplotly(p)