I used to use HotBot all the time to quickly check the difference in search results between many search engines. Now it looks like HotBot gives the searcher on two engines to choose from, Google and Ask Jeeves. I think back a year or more ago, it allowed you to search with AltaVista, Inktomi, Google, Ask, AllTheWeb and others. I guess since there are only now four main players, two being new to the game (Yahoo! and MSN), there was a need to drop some. But specifically, according to a thread over at WebmasterWorld, HotBot has dropped Yahoo! as an option.