I found two metalink notes which have detailed step by step instructions to do ssh user equivalence:
329476.1 Read the section about setting up ssh.
You can stop using rsh/rcp and set up ssh using these notes easily. rsh/rcp has following disadvantages:
1. It is not secure.
2. rcp uses standard ports below 1024 to transfer files, Available free ports in this range are free, so if you have to rsh a lot of files in parallel, it won't succeed.