It is this nature of the web that mandates search as the best possible interface for the web. At any moment an even better solution to your current need may come along, how else would you know except to search for it?
By contrast your iPhone (or iPad/iPod) is tiny. It's storage currently maxes out at 64gb, that's virtually nothing. The important point is this: What's on your iPhone is your content. Every byte of that content was loaded by you, because you want it there. By contrast, what's on the web is a free for all. You have to sift through the web to find content of interest to you.
This makes a big difference when you develop for the iPhone. iPhone apps center around your content, your data, things directly meaningful to you.
If you have a search-based web app and you want to make an iPhone app as an interface to that search-based app, consider turning your app inside out:
- Make the home screen a list of recent or saved searches, or a list of bookmarks. Chances are, users are going into your app from an iPhone to find something they already know is there.
- The second screen can be a search screen to obtain new results, but the home screen should always be populated with content already relevant to the user.
- Remember, stay focused on making the user's previous finds easily accessible, especially if there is a way to save or bookmark results.
- Allowing users to find new things on the web is great, but first make sure that what they've already found is still easily accessible should they want to find it again!
Sometimes this isn't what a user wants, but most of the time it will be. Consider your App, consider your user base and see if this kind of design works for you.
PS. make sure you aren't stomping all over a bunch of privacy issues while you are at it :)