Does Google allow other people to use their "Did you mean" API?

Pygoogle has an api call for that

http://pygoogle.sourceforge.net/dist/doc/public/google-module.html#doSpellingSuggestion

>>> import google
>>> google.LICENSE_KEY = '...'
>>> google.doSpellingSuggestion('pithon')
'python'

doSpellingSuggestion I believe is the api call. There is a good example here

Update
As people have noted, the link is broken. Here is a Wayback Machine's archived copy.