Umlaute in Terminal.app
Although I am using an english OS and now have an English keyboard I do want my German umlauts to be properly displayed …and I also want to be able to input them and not get some weird number sequences. Terminal by default uses UTF-8 for output. For having the proper input encoding you need to provide a few environment variables (e.g. in your .profile) and then you are set.
export LC_ALL=en_US.UTF-8
export LC_CTYPE=UTF-8
export LANG=en_US