Yes! More tweaks for Firefox 2. Now, Firefox 2 now has a spell check feature that checks for spelling errors in text entry fields. However, by default, it only checks multi-line fields which leaves you to still be open to spelling errors for single-line fields. But we can make Firefox check those automatically with this tweak.

• Bring up your about:config page. If you still don’t know how, read how to do in-depth configuration.
• In the “Filter” field type layout.spellcheckDefault.
• As you can see, the integer value is 1. Double-click on it, then enter 2 as its new value.
• Click OK.

This should work the next time you run Firefox.