I don’t know why I never noticed this before, but Safari has a built in spell checker. This come in extremely handy if you comment on a lot of blogs, or fill out a lot of online forms.
When I comment on blogs, I was spell checking the stupid way… I would write my comment in TextEdit, and then copy/paste into the comment form. Finding this just totally streamlined my commenting process. I don’t know why this option isn’t turned on by default.
tip: you must have your cursor in a text field on a page (or in the address field) to access the spelling menu items. If it’s not, those items are grayed out.
found via Electric Spork