> I switch back & forth from 3G fairly commonly. Is there a way to install what in Windows would be called a shortcut?

What is your reason for "switching back and forth"?
In general, the iPhone will use Wifi preferentially if it is available, and cellular connectivity when it can't get Wifi. The only reason I can see for turning 3G OFF is if you spend a lot of time in 3G "far fringe" area, where the iPhone "thinks" it can get a 3G signal, but really can only get Edge. I've found very few such areas myself.

> This is a bit cumbersome:
> Settings/General/Network/Enable 3G

It can be made less cumbersome by utilizing the multitasking or rapid switching feature.
Open Settings/General/Network/ and leave it there.
Single-press or double-press the Home button and go to whatever App you want to work with. If you feel a need to alter the 3G setting, double-press the Home button, scroll through the App tray to find Settings, tap it, and there you are at the Network page.

> Speaking of shortcuts, can I create or delete folder-groups for my apps? For instance, I need no Financial apps. I could kill that folder.

You can delete Apps you install and Folders you create (but only by removing the Apps from the Folders).
You cannot delete "Apple-native" Apps (like Stocks).

Jim Saklad