The principal of having keyboard shortcuts for users to access/navigate a website is surely a good one but there are serious drawbacks that have so far stopped me from implementing them on any of my sites.

Can members give me their experiences, knowledge and opinions on this subject please?

I can easily apply accesskeys to A, AREA, BUTTON, INPUT, LABEL, LEGEND, and TEXTAREA but should I? My current project is for a large, public-facing passenger transport information site. Its almost ready (sorry, not allowed to post URL yet) and has achieved WAI Priority 3. Obviously I want it to be as accessible as possible but will adding accesskeys actually help?

My concerns:

• Accesskeys are invoked differently on varying OS/Browser combos and not all browsers support them.
• The number of different accesskeys is limited by standard QWERTY keyboard which may not be available to all users.
• The Big One... The keystroke combinations may conflict with a reserved keystroke combination used by the OS, other software, adaptive technologies, or user agents either currently or in the future.

Please see:
wikipedia: Access key
Using Accesskeys - Is it worth it?
Accesskeys and Reserved Keystroke Combinations

Can't contribute much. I gave up on them long ago because they inevitably conflict with personal keyboard shortcuts and there's no way to avoid that, not that I can think of anyway.