To avoid saving the truecrypt password in history files and mounting the Truecrypt partitions on bash the following trick helps:

history -d $((HISTCMD-1)) && sudo truecrypt --mount <PATH_TO_TRUECRYPT_VOL> --non-interactive -p <PASSWORD>

This will avoid saving the password in the .bash_history file and also mount the truecrypt volume from the command line.  Of course, if you use this in a shell script then the shell script will have the password in it, so you must not do that.