Google auto complete (even with safe search on) returns some pretty eyebrow raising results.. Are these results really appropriate for a classroom?
If you are looking for the same functionality as google safe search without the auto complete and adverts visit Safe Search
I just tried the "is it" test myself and was amazed by what I got as suggestions. You can see the suggested searches at
http://twitpic.com/z32la
Some are quite innocent but others are not the sort of thing I would like to see coming up on a screen at school.