Thanks, I need to re-qualify my question:

what if its not a number and you can't do math on it?

e.g.
list1:
mary
eve
delilah

list2:
joseph
adam
samson

output:
mary joseph
adam eve
samson delilah


for i in `cat list1`; ... for j in `cat list2`; ... do ... print $i $j ... done

any way around this?