Some websites automatically place the cursor in important text boxes for you. Others are not so courteous. A quick Firefox tweak makes it easy to jump right to the text boxes.
At the technology blog gHacks, they've shared a simple about:config tweak to make text box navigation easier. Unfortunately there is no hack for making the first text box on a page automatically in focus. You can however make jumping to the first text box really keyboard friendly.
Type about:config in the address bar within Firefox. Use the filter function to search for accessibility.tabfocus.
The default value is 7 which means when you hit the tab key the focus jumps to any form or link element on the page. That isn't particularly efficient when you're trying to keep the focus on the text fields. Changing the value to 1 makes it so the tab key will only jump the focus to text fields. With that simple tweak a tab stroke or two will jump you right to the text field, no wasted key strokes or mousing required. Quicky Jump to Text Fields in Firefox [gHacks]