Two quite annoying bits to remember so lets blog 'hem. Under a tty the keyboard may have a bad layout, I know perfectly changing it under X with setxkbmap but I usually Google for the console. The answer is loadkeys. Running loadkeys -d will print the current map file that gives an idea where to find the maps. Switching the map works like loadkeys /lib/kbd/keymaps/.../fr-latin1.map.gz, in other words just pass the map file. Now to come to the other annoying command to remember is the ability to cut off the beep. It works with setterm -blength 0.
Update: passing the locale directly to loadkeys works (thanks Boris), neither the help output nor the man page mentions this.