Template:Panels

Usage

{{Panels
|tab_1         = name of tab (i.e., Something)
|content_1     = contents of panel (i.e., Here's some content about something.)
|tab_2         = name of tab (i.e., Another Thing)
|content_2     = contents of panel (i.e., Content about this other thing.)
[...]
|tab_N         = name of tab (i.e., Something Else)
|content_N     = contents of panel (i.e., Some information for this last thing too.)
}}

You can as many tabs/panels as you like, tab_1 through tab_N, but you don't need more than two (well, technically you only need one, but then why bother?). It may also get cluttered if you have too many tabs, but that's a matter of taste. contents_# can be as complicated as you like, as long as nothing is left open. The appearance can be adjusted more by writing custom css.