Post installation

hello,
i'm going to create a (my friends) portal community where every users'll be able to have his/her own gallery, creating own category, own links directory, own audio/video casting, own forums, own books, etc..

I initially thought to a multi-installation system but in this way i had to enable manually every user (and it'll be more heavy) so i discarded this option.
I though there's some way to do this and maybe some access control module will enable me to let users being indipendent from site administrator to:

I'm wondering how I can put polls within a page, I want to have several polls in each of my pages but I can't see any way of doing this, I just see that I can add a poll somewhere.

Thanks in advance.

Does anybody know if it's possibile (and how) to let visitors (anonymous users) change theme?

I'd like to let people choose between two themes, for usability: one very nice, and one very simple and readable.

I saw something similar at http://themes.drupal.org/

Thank you all
gerlos

It has taken me a week to get the hang of drupal, but I must say I'm VERY impressed.
I am experiencing a problem, however. I would like users to be able to post inline images to the forum, but so far what I have is that logged in users can post images as such, but they are not contained in the forum message at all.

The inline tag just shows up as an inline tag in text if I add it (and the module is of course installed, access controls are ok etc.).

Any tips as to how to obtain this result ? Take a look at what is going on now, please:

I had Drupal working with the Taxonomy Access Module, and whilst trying to configure the Blocks module I entered the following code in the PHP pane.

I was attempting to display different categories for different users.

global $user
if (is_array($users->roles) && array_key_exists(4,3, $user->roles)) {
return TRUE;
}

It complained about the above code, but all was still working, unfortunatley I accidently deleted the (s) in the (exists),
and now the whole of the site has stopped working.

Say I have a personal website, that has content I only show to members, and I also have a livejournal presence.

Now say, that enough of my userbase on said personal site stems from livejournal users, I would like to allow livejournal users to log in via the livejournal.module freely without hassling with making an account on my site. However, I want to restrict all other account requests to admin approval, cause I don't want any random Tom, Dick, or Harry to be able to see my nudie pics and read about my anal fissure surgeries.

How would I do that?