While reading through UNIX powertools tonight, I came across jot. This nifty little utility will print a sequence of numbers, which can be used to iterate through a loop:
for i in `jot 5` do echo $i done
Using jot in this way is typically faster than other mechanisms (e.g., i=`expr $i+1`), and is easier to read IMHO. Jot it up yizos!