Phlo is a handy little Universal iOS app which lets you search a bunch of different search engines simultaneously. Just tap in your search term and then hop between various sites using the popover sidebar list.
The iOS version of Phlo is the offspring of the OS X version, and your searches can be synced between the two. You also get access to your own search history, and you can reuse a search as-is, or with tweaks.
You get 30 built-in searches, but you can add your own, too. In this respect, it’s a lot like using something like Launchbar on the Mac to search the web quickly.
We’ll see how useful this in iOS 7, which has a greatly enhanced Siri-powered web search (the results are shown for you right there in the Siri screen, including a straight web search, pictures and alternate sources like Twitter (personalized using your own account). Then again, you have to talk to Siri, which can be a little embarrassing in public.
Phlo for iOS is $3.