It's been one of the aggravation points since the App Store first launched and we began accumulating all these magnificent toys: how the heck do you manage 11 screens full of icons scattered all hither and yon? iTunes 9 gave us some control, but lacking an organizing principle things continued to be challenging.
No more, at least not once 4.0 ships. The new Folders feature will let you throw apps of a feather into a folder grouping just by dragging and dropping, and you can then treat the entire collection as a unit, moving it from screen to screen or tossing it into the app dock as you like.
This may not be a killer feature for those who only keep one or two app screens active, but for heavy App Store customers (you know, the people who send Apple that reliable 30%) it's a godsend. At the event today, Steve told us that it would take the iPhone's homescreen capability from 180 apps to a whopping 2,160, so, um, we've got some app downloading to do before the new OS releases this summer.