i've asked around, and had a few more suggestions:
(may require you to run "shopt -s extglob" first to enable that functionality)
Code:
find . -maxdepth 1 ! -name *.type | xargs rm
you'll note i'm not using "-rf" anywhere - that's because -rm should be considered dangerous. the "-r" means "if a folder is named like this, remove it and everything in it", which is sometimes not what you want. the "-f" means "don't ask, don't check, just kill it dead", which is usually the last thing you see before shouting "oh ****"