Trick to copy meshes and materials over from game maps.

[Nawrot]

First I need to write small warning:
Similar method worked in old UT2004, but was quite dangerous. You will be using reference to material, not your own copy of it. So any modifications to it will change original map and render your UT3 different from officially released and thus make it incompatible for lan or internet play.

How to copy static mesh:
Save Your map and open one you want static meshes from. Select ones you like (not more that 5-10 at once) and use "Editor" menu "copy" function. Do it from there or it will not work. Then reload your map (it is in recent under Files menu). and again go to EDITOR and do paste. Meshes should appear in orginal coordinates from source map.

How to copy material:
Again open source map, and find material you like (should be on BSP). Then right click on it and do "Synchronize to General browser". This should open general browser and focus it on texture you like. Now without closing browser reload your map (in recent files) and you can apply materials from General browser.

Ps. AS I said this method is potentially dangerous, so be careful and do not modify Epic's assets. (ie. game asks you if you want save Source (Epic's) map, say NO to it.)

[SmokeRingHalo]

In UT2k3, I released my first map with a fudged static mesh package from using this method and I caught a LOT of flak from the community for breaking peoples games until I went back and fixed the various static mesh problems. Long story short, now that I'm older, wiser, & more patient, I've learned the error of my ways and don't recommend this method. It doesn't take much longer to simply open the properties of the static mesh you want to copy to see which package its in and then open that package.
That said, I'm glad you put a warning with this.