This is a great extension and it makes for excellent, comfortable, mouseless browsing (especially after resetting the magic keys to around home row).
Things that would make it great would be to reassign the trigger key (e.g. to right-alt). Also, I think there is a bug (?), it looks like it is inserting an html tag into some form textboxes / rich text editors: hints id="hah_hints". You can see this by going to the FCKEditor page and their demo page, then clicking the "source" button in the toolbar. Really not cool to have these extraneous tags for CMS stuff.
Aside from that, this is a super-awesome extension, thanks for making it!