Google has lauched an update to their spell checking (in documents and presentations) that "grows and adapts with the web, instead of relying on a fixed dictionary. This update has a few big advantages over traditional spell checkers:
1. Suggestions are contextual. For example, the spell checker is now smart enough to know what you mean if you type “Icland is an icland.”
2. Contextual suggestions are made even if the misspelled word is in the dictionary. If you write “Let’s meat tomorrow morning for coffee” you’ll see a suggestion to change “meat” to “meet."
3. Suggestions are constantly evolving."