MultiSearch — free app let's you search 20 search engines at once

MultiSearch is a free app that lets you search multiple search engines simultaneously. These include Google, Bing, Wikipedia, Yahoo, Amazon, eBay, YouTube, Flickr, iTunes, AppStore, Last.fm, Panoramio, Twitter, Facebook, LinkedIn, Digg, and FriendFeed. You can choose which engines you want to search, and all the results are displayed in a single, browsable view. Plus, you can enable geolocation such that the search results are related to your current location. Other features include the ability to save your keywords, bookmarks, auto-complete, and search history.