The second engine, which just displays two screens from Bing and Google is called Bingandgoogle which doesn't score much for originality, but is very accurate. Bingle does exactly the same job and you cannot really tell the two apart; the only difference being that you can switch results entirely to one search engine or the other.
Of course, if you don't like any of these you can always try Tripleme which does a search across Yahoo, Google and MSN Live (which I'm guessing is pulling results from Bing).
GrabAll allows you to compare two pane results for Google, Yahoo, Ask, Bing, DMOZ, AltaVista, Gigablast and Looksmart.
Scour lets you check out results from Google, Yahoo and Bing with a nice sort option.
Searchboth will compare results from Google, Yahoo, Ask, Dogpile, MetaCrawler, AltaVista, Looksmart and Websearch again in a two pane window approach.
Soovle takes a different approach by providing on page access to Google, Wikipedia, Amazon, Answers, Yahoo, Bing and YouTube, Type in your keyword and Soovle comes up with alternative terms - click on any of them and your search will be run on the appropriate engine.