looks pretty similar to this one:
Code:
http://www.youtube.com/watch?v=PRPQIJJ6EGM
It is done by hex-editing files in your 4story/tcd folder (TClient.exe uses these at runtime, so you can also edit TClient.exe, after it has loaded the files into memory, as Superx321 did).
Some details are here:

(but the explanations are very weak/confusing, as ppl told me...).
Good to see that someone is finally using this!