Are conditional forms good practice on the iPhone?

Question

I want to allow the user to enter data on an iPhone.

I've got a screen that will look like:

            New Animal

Name:   Enter Name

Type:   [ Mammal ]  |  Amphibian 

Number of feet: 2

Or when Amphibian was selected:

Name:   Enter Name

Type:     Mammal    |[ Amphibian ]

Preferred Water: Salt Water

So the section below changes depending on the type selected.

Is this good or bad practice on an iPhone? And if it isn't, what's the best way of doing this?

Answer 1

Yes, but probably only when using multiple screens. First screen: type name, hit next. Next screen: select type. Next screen: select number of feet or preferred water, depending on last selection.

Something similar to setting up an account on Mail. You select where your account is and the next screen depends on which account host you selected.