Hi,
This may take a bit of coding but the only thing you can do besides give him your password is to setup an account creation area,
if you take a look at this documentation here:
http://www.cpanel.net/manual/remoteaccess-php.html
You could submit the variables $acctuser, $acctpass and $acctplan from a html form which would enable him to create an account with the details needed,
only problem would be that a plan would already need to be created with the specs that suit him,
the more features you require, the more coding it takes,
if you spend time on it though, you can come up with a really cool system, I recently finished coding a system allowing my resellers to create reseller accounts of their own through a small separate control panel,
works very nice :D
