I have been using an iPhone for the past two weeks and it’s pretty clear to me that the only thing that is going to stop me from using it more and more to find things is a fatal car crash.  That’s why my loved ones and I are glad to hear about a number of voice search services that are starting to emerge.

Here are two iPhone voice search services due out soon:

AT&T (thanks Dick)

Say Where (thanks Greg)

At this point it’s hard to say what the optimization strategies will be for these services as it seems like they will merely be voice interfaces into standard search engines.  But my guess is there are going to be some differences between how people request information by typing v. speaking.  And those differences might have an effect on how a voice search engine decides to display/play data.

It will be important to figure out how most people will use these services.

My guess is that users will make a voice request and the results will be read back and be displayed on a map interface.  The user, who will no doubt be driving and trying not crash, will take a quick look at the map and touch the map icon that looks most interesting, expecting to hear more about the listing.

For example, if I were on an iPhone mapping function and looking for a restaurant nearby, it would be great to be able to hear some of the reviews of that restaurant while driving.

Just as video is starting to become a strong element in local search engine optimization for universal search, it may make sense to start adding audio files to your site to help stand out in vocal local mobile search.