This add-on provides configurable keyboard shortcuts for many actions (42 actions in version 0.3.1 of the add-on) and a dialog to customize them.
Shortcuts can be either single key (for example 1=previous tab) or a key combination (for example Ctrl+space=go to homepage).
Defaults are based on Opera 9 single key shortcuts:
Move back in history z
Move forward in history x
Switch to previous tab 1
Switch to next tab 2
Go to homepage Ctrl+Space
Focus addressbar F8
Reset zoom 6
Zoom in 9
Zoom out 0
All shortcuts can be changed, added or removed in Tools -> Key settings
Source code tarball available at http://keyconfig.petricek.net/