Clicking on a selected link without using the mouse, using Firefox

You can do this with the Return key, so Ctrl-F, type the text of the URL, then hit escape. The focus should remain on the link you had highlighted. Hitting Return will open the link.

Use the apostrophe-key ' to enter Quick find (links only) mode.

Maybe also useful: F6 to move the keyboard focus (hard to explain, just try it out).

http://www.accessfirefox.org/Firefox_Keyboard_and_Mouse_Shortcuts.html