( EDIT: stumbled on a proper thread: http://talk.maemo.org/showthread.php?p=386536 moderator feel free to delete this post. (why can't I do it myself?))

Since I didn't find this already with a search... As you might have noticed, the button to configure osso-xterm toolbar shortcuts is gone in Maemo5. I used gconftool-2 to copy over my settings from my N810, like this:

This gave me the | symbol as a shortcut on the toolbar next to ctrl shortcut.

As usual, be very careful messing around with gconftool, you can easily mess up things.