cd ~ will not work on bourne shells (the default for many unix'es)
I'm assuming by 'anything except cd...' you mean it as it's written (ie cd with no options to get to the home dir).
In which case, cd $HOME should sort you out.
If you want something foolproof though:
Code:
cd `grep -e "^username:" /etc/passwd | cut -d ':' -f 6`
