Ok, if you really want to know, I will make a quick tutorial right here. If you know how to import a texture, skip to the second part.
FIRST PART
Importing a Texture
First you have to play the map you are working on with no bots, no HUD, a hidden gun, and make your crosshairs color black so they don't show up. All this can be done under the preferences menu. Then find a suitable view for your screenshot, and press F9. THe game will take a pic of whatever you are looking at and save it as a .bmp in your UT/systems folder. I recommend doing more than one, to save time.
Now open up an image-editing program, open the pic you want to use, and change the image size to
256x256 or 512x512.
It doesn't matter how big, but it must be square, and if its real big makes your package much larger. Then adjust the color settings to 256 colors, and make it 8-bit.
Then save it somewhere as a .pcx file, named
"Screenshot", with a capital 'S'.
Now open up UED, open your level, open the texture browser, and import your new saved and converted pic.
In the box you get, put in the package field "MyLevel" (case sensitive, again), and in the group field put none, and in the name make sure it's "Screenshot". Also make sure "Generate Mipmaps" is unchecked. THen click ok, and it should load your pic under the "MyLevel" package.
PART TWO
Setting the Screenshot
Click on your screenshot pic in the texture browser so its highlighted, and then at the top of UED, go to
view; level properties; level info.
Where it says "Screenshot", click once, and then click "Use". THe name of your screenshot should appear. Now close the level properties window, save your level, and try out your screenshot.
There you go. hope i didn't go overboard. I would have sent you to unrealed.exe but the site seems to be gone.
You can also do animate screenshots, but they're not really necessary.