question on loop

I have requirement where i have to create ssh keys for user on given list of servers and collect all the key from each server and copy into all servers.

Example :-

node1
node2
node3

user:-

webadmin

create key for webadmin on three servers and collect web admin key of all three servers and place into each server

I will pass host list as

sudo ansible-playbook rakesh.yml -i /home/rak/hostlist

Can some one help me with this kind of requirement.
Any Help is much appreciated

That sounds a bit like this example from the loop documentation in ansible: http://docs.ansible.com/ansible/playbooks_loops.html#looping-over-subelements

Hope this helps.

Jon