There is always the Kong toy with kibble in it and peanut butter to cover the hole. Then freeze it for a couple hours before you give it to the dog. My dogs LOVE this and will stay occupied with it until every morsel is out. Unless they end up pusing it somewhere they can't get to it. LOL Like under the couch.

Also the link Seravieve posted has several other toys that would work too. Busy Buddy toys are all enteractive like that.