I wanted to put a WP-Admin link on my blog, but one which only showed to me whilst I was logged in.
So hunting through the WordPress Codex I tried to find something like is_admin(), but couldn’t find it. Then going through all the PHP files I found this function current_user_can(capability) which returns true or false if the logged in user can do that capability. Next I had to work out a capability which only admin could do, but a quick look at the source code showed that it should be possible to enter an integer which related to a level.
So finally I have this on my blog:
<?php if(current_user_can(10)) { ?><a href="/wp-admin/">WP-Admin</a><?php } ?>