I have added support for access keys on the jQuery Ribbon.
To show the info about the access keys, hold the alt button.
To use with Internet Explorer
Hold the alt button and click on example the button with 3 on the keyboard. Then release the buttons and click enter to switch to that tab.
To use with Firefox
Hold the alt + shift buttons and click on example 3 on the keyboard to switch to that tab.
Hint: To toggle the menu, use the “1” access key to open it, and the same to close it.
The latest release is published on CodePlex.