It's not that different from N900 (http://wiki.maemo.org/Remapping_keyboard).
You can change the hw kb layout using setxkbmap and/or editing /usr/share/X11/xkb/symbols/nokia_vndr/rm-680 file -- here's mine, modified for Polish locale (and for ADOM, too ). Polish characters are accessible with SYM+letter. Symbols menu pops up when SHIFT+SYM is pressed.