[R] Summary grouped by factor

[soeren.vogel at eawag.ch]

### example:start
v <- sample(rnorm(200), 100, replace=T)
k <- rep.int(c("locA", "locB", "locC", "locD"), 25)
tapply(v, k, summary)
### example:end

... (hopefully) produces 4 summaries of v according to k group  
membership. How can I transform the output into a nice table with the  
croups as columns and the interesting statistics as lines?

Thx, Sören