The first part is easy: just find a skin that has something you want, download it, then cruise the _main.php file until you find the detail you're after. (You'll have to excuse me for not finding the code for you, but it's 7:15am and I'm fairly well likkered up.) The second part isn't so easy. You could put some energy into understanding locales OR just copy the ? flag image in both the flag folders as the locale flag you want to replace. The hardest and bestest bet is to understand locales, which aren't so hard after all.

Even after a few heavy duty bourbons.

A locale is simply "language-NATIONAL FLAG" done in two letter codes. After that the locale lets you say some simple things about your locale. How does this localization like to show the date and time? What day is the start of the week? So what you want would probably be something like copying "en-UK" as "en-NN" and let NN turn into the ? flag. After that you could decide your new locale likes to have y/m/d instead of d/m/y. Or whatever. Anyway you'll get the ? flag from having an unknown 2 letter code for your nation.

Always best to learn new things eh?

Thank you EdB !

You've given me some pretty good clues about where to look and how to go about :)

I will follow that (or try anyway), and by the time I get it done you'd probably be back to yourself (he he)

Thank you for your help

I'll let you know how I got on. (I'm sure you're sure of that)

Always best to learn new things eh?

That's the spirit I like!

(GMT here - +7 for you)
.

OK, you were right (of course)

the first part was really easy. I downloaded the Basic skin, and found it straight, there it is:

<?php locale_flag( $Item->locale, 'h10px', '', 'left' ); // Display flag for post locale ?>

I just put that where I wanted, and flew away to the next thing :)

The second thing, as you said, was a little more tricky:
I got a map from a link given on the Docs, resized it and downloaded it to my folders.
Then I checked out in the back office what the UK the Regional Settings were, click on 'create new locale', and copied the infos there.
What tricked me was how to change the flag, and this is where you helped:

A locale is simply "language-NATIONAL FLAG" done in two letter codes.

Special note about the 'two letter codes' :)

It's all done now, and [u]I even made a World flag[/u] !!!

Thank you very much
Hope you're better now.