There have been some interesting posts recently about the iPhone "Springboard". I don't know if that's the official name, but in any case, it's the "home" function of iPhone that lets you page through apps and launch them.
I can identify with the problem; I have 7 screens worth of apps and I page through them constantly. But I think the solutions proposed in the above two posts are too complicated, and I agree with Fred about why Tog's #1-#3 solutions are not good.
My solution is very simple, and is around containers. We simply need containers for apps. I don't know if they are "folders" or "playlists" or "groups", well, let's call them "groups" for now. iPhone tries very hard to hide the file system from the user, even though they have a complete one inside. But Apple has many groups all around the iPhone and OS X that I would call "domain-specific containers". These would be playlists in iTunes, Events etc in iPhoto, Groups in iCal... i.e not general-purpose folders, but hierarchies for the purpose of organizing items in a particular domain. iPhone App groups fit here well.
So, how would this work? Here's a simple lo-fi wireframe.
On the left, you see a regular iPhone view. On the right is what you see when you tap on a Group.
You'll see that the four über-apps have disappeared. This is because when you are already in the context of a group, you don't care about those; you only care about this group.
Why is this a superior solution?
It keeps everything about the Springboard that we already have. You still have pages, you move apps around exactly the same way, you can still search for them, you still have the four "über-apps" that are always visible etc.
Unlike Fred's and Tog's solutions that require a computer to manage them, these groups are fully manageable on the go without a computer. This is important, since I know many people (and also myself) who don't connect the phone to the computer for an extended period of time.
Furthermore, managing apps is something that you do when you get the urge. Apple recognized that buying apps also falls in this category, which is why they let you buy, delete and do everything with the apps on the phone without a computer. So you have a bunch of apps and you look at them on your phone and suddenly decide "hmm, I would like these three to be in a group". Being able to do it right then and there is superior to having to remember (or rather, forget) this for a later time when you have access to a computer.
The group interface is not limited to 16 apps. Similarly to Documents and Downloads stacks on OS X dock, it can change its appearance based on the number of apps: if it's greater than 16, switch to table/list view, where the amount of apps can be endless with live filtering. (Another option: keep the magic number at 12, and keep the four über-apps in the bottom.)
Here are the things you can do.
Moving an app to group. Just tap and hold like today, until you see apps and groups wiggle. Drag and drop an app on to a group. It goes there.
Moving an app to parent group/back to master springboard. Tap and hold on an app while looking at a group, and either just drop it in the "Back" button; or, the "wiggle" version of Back button could be something that is more obviously a (bigger) drop target.
Moving groups around. Fully same as apps today. Put them onto the "quick launch" zone if there is room etc.
Creating subgroups. I don't see it as necessary. But all the above scales for nested groups as well. Apple does not have playlists within playlists, events within events etc for a reason.
Deleting a group. Just tap and hold for "wiggle mode", hit the X icon in the corner of the group, and tap it. And then see some explosion animation that removes the groups and explodes the apps back to springboard.
Move many apps to a group. See above; if you put more than X apps in a group, the group stops looking like a mini-Springboard and instead switches to table/list view. (Or, maybe a group can have multiple pages in it.)
Creating shortcuts, one app in multiple groups. This is Tog's #5. On one hand, shortcuts are too abstract on a filesystem level; on the other, they seem to work in domain-specific groups (iTunes playlists, iPhoto albums). I can't think of a good way to manage this on the device, but surely you can do it in iTunes, similarly to playlists.
Creating a group
The only thing missing from the above is, how do you actually create a group? (Leaving aside iTunes on computer where you could do it in many ways, let's focus only on the device for now.) Well, let's say you are looking at an empty space on your Springboard where you'd like to see a group. So, you just tap and hold (which currently does nothing on empty space) and you get an interface for naming a group, and you name it, and voila, you have it.
If Apple wants to do multiple things with this gesture, they could introduce indirection through choices. I.e
- tap and hold on empty space
- select "Create Group" from among the options
- Name group