Google Sets labs is an experimental web tool to automatically create sets of items. You can enter few keywords for specific set of items and allow Google Sets tool to dish out more similar items. It has two options, either show large set with more than 15 items or small set with less than 15 items. For example: enter item names like bmw, honda and mercedes benz.
Click on small set button to see more such similar item words. Results are clickable and takes you to relevant Google search page. Following is the result of car words example.