Google announced that in about 30 days from now, the way they handle AdWords match types for exact and phrase based matching will change. Going forward, Google will auto-match for phrase and exact match even for variants including misspellings, singular/plural forms, stemmings, accents and abbreviations.
Why? Google has said that over 7% of all queries contain misspellings. Google also explained that Google's organic results already do this and they want to make sure the AdWords results do the same. Google added that in early tests it has led to an increase in clicks by 3%.
Here is an example:
Don't like that Google is doing this? Don't worry, you can turn it off. Once Google activates this log in to AdWords and select the campaign settings tab. Under “Advanced settings” select Keyword matching options. There will be an option to turn it off there, here is a picture:
Forum discussion at WebmasterWorld.