It's very simple to select a different keyobard layout with the KDE LiveDVD or indeed with a KDE installation on your HDD. It's the first thing I change when I boot a SL KDE LiveDVD, since the machines on which I boot a LiveDVD don't normally have a US keyboard.
1. Right-click on the US flag icon in the System Tray and select 'Configure...'
2. Click on '+ Add'
3. Against 'Limit selection by language', select a language of choice. Let's select 'English' because I have a British keyboard.
4. Against 'Layout', select 'English (UK)' as I have a British keyboard, and click 'OK'.
Optionally, you can then click on a keyboard layout in the list of layouts in the Keyboard Control Module window and either delete the selected layout, or move it up or down, or preview it. If I have a laptop with a British keyboard, I usually select 'English (US)' in the layout list and click on 'Remove'.
5. Click on 'Apply'.
6. Finally, click 'OK' to close the window.
With respect to Step 3, you can select from a long list of languages for your keyboard layout(s), many of which do not use the Latin alphabet (e.g. gre (Greek), Russian, Thai, chi (Chinese), and so on).
If you have configured more than one keyboard layout, just click on the flag icon in the System Tray to select the one you want. On my laptops I have more than one keyboard layout configured so that I can type more easily in the languages I know and also use external USB keyboards for those different language layouts. On my main laptop, which has a British keyboard layout, I have left the US keyboard layout as well as the British keyboard layout in the list, as I have to use an external USB keyboard with the US layout in some offices.
You can also configure keyboard shortcuts to switch keyboard layouts if you wish. I'll leave that as an exercise.