Selected menu item in the layout

Well you can use link_to_unless_current, but you won't get
class="selected". Instead you'll have to code your CSS based on the
existence of a link or not.

Right well, in that case you need to do something more robust anyway
because you'll want the tab to be an active link when you are on any
of the subpages.

However, you can create a helper that will emulate
link_to_unless_current with your own semantics so your template
doesn't get bloated.