Script Summary: Alt-d (customizable) puts cursor focus on the first search box or input box on the currently viewed webpage. Alt-d a second time moves the focus on next one. Ctrl-d swaps the typically narrow input field for a larger one. For easier, larger font, typing and spell-checking.
Version: 19th of February 2010. Shift-alt-D allows to cycle backwards through a form's fields.
With control-d convert the current small sized field into a larger textbox (a html textarea), use tab-enter instead of enter to send the input or hit control-d again to have it revert to an input box. To cycle around inputs with the larger text box hit alt-control-d.