A somewhat different approach using ggplot2:
dat <- read.table(text = "A B C D E F G
1 480 780 431 295 670 360 190
2 720 350 377 255 340 615 345
3 460 480 179 560 60 735 1260
4 220 240 876 789 820 100 75", header = TRUE)
library(reshape2)
dat$row <- seq_len(nrow(dat))
dat2 <- melt(dat, id.vars = "row")
library(ggplot2)
ggplot(dat2, aes(x = variable, y = value, fill = row)) +
geom_bar(stat = "identity") +
xlab("\nType") +
ylab("Time\n") +
guides(fill = FALSE) +
theme_bw()
this gives:
When you want to include a legend, delete the guides(fill = FALSE) line.