What is 'out there' isn't a mystery if you know where to look. It starts by
"What modules do I have installed?"
If you know that your users have something on thier profiles, thats a great place to start.
So let analyze this profile on the demo site:
http://demo.jamroom.net/jrNingja/demoadmin/audio/80/song-dance
We can see that they have:
* TIMELINE
* AUDIO
* BLOG
* EVENTS
* FORUM
* GALLERY
* GROUPS
* PLAYLIST
* POLLS
as tabs on their profile. This means that at least those modules are active on the site.
Most modules contain an index.tpl file, that means that they provide a common list for all the items from the site regardless of profile. Its probably that that you want to link to from the main menu.
We can see in the URL in the address bar that the structure is:
sitename.com/(profile name)/
(module url)/.......
So we can go check if the module url also provides us with a site wide list. In this case the URL we are on is the audio one, so remove the profile name and check out:
http://demo.jamroom.net/jrNingja/audio
Yup! Thats got a list of them all. So now make a menu url pointed to that location.
And repeat.
For the url's that are active on the demo site, we see that these all have lists:
http://demo.jamroom.net/jrNingja/audio
http://demo.jamroom.net/jrNingja/blog
http://demo.jamroom.net/jrNingja/event
http://demo.jamroom.net/jrNingja/gallery
http://demo.jamroom.net/jrNingja/group
http://demo.jamroom.net/jrNingja/playlist
http://demo.jamroom.net/jrNingja/poll
So you can do the same for your site. Just because a module has that page available, doesn't mean you HAVE to put a link to it in your menu. Its your site, you can choose.