Admin-only parts of layout

I’m interested in code allowing me to hide specific content of page when I’m unlogged user or logged, but not an admin.

I’m porting my old layout from Jogger.pl to stand-alone blog. I just miss <ADMIN_BLOCK></ADMIN_BLOCK> and <LOGGED_USER_BLOCK>, <NOUSER_BLOCK> template tags.

Is there any way to put some if() in template, that will enable me to, for example
show my email only to me and logged users
show disclaimer to new (unlogged) users
etc.