I realize that you can't overcome the iPhone's "built-in" startup delays; however, there is a potential workaround for folks who have jailbroken their iPhone: Backgrounder. Unfortunately, when you leave SearchDial in the background using Backgrounder and return to it, the keyboard is not shown. You have to tap cancel and then tap the input field to get the keyboard back, defeating the benefit of the quick startup.
While you may not wish to encourage (and surely wouldn't want to require) jailbreaking of iPhones to run SearchDial, a tweak to the interface to play well with Backgrounder -- e.g., [searchField becomeFirstResponder] within viewDidAppear -- would allow all of those folks with jailbroken iPhones to enjoy near-instant startup of SearchDial and have no effect on non-jailbroken iPhones. :)
The only reason its not in viewDidAppear is so it doesn't pop up after you go to the help screen if it wasn't already up. however, thats probably a lower-value use case than the one you describe. i'll do that for the next version if it doesn't slow down normal starup.
I appreciate your concerns on making sure startup is as fast as possible for everyone. If you discover that the this change adds any detectable slowdown to startup, before abandoning the idea please consider adding it as an option (e.g., "Backgrounder compatibility: ON/OFF") and only invoking becomeFirstResponder within viewDidAppear based on the preference (I'm assuming/hoping that settings would be loaded at startup anyway & checking one wouldn't slow things down).
Thanks again for considering this tweak... and for bringing such a great app to the iPhone!