[Ted L. Nancy]

I understand that landscape is very popular, but is there any way to disable Mail and Safari from turning landscape when I happen to tilt my phone? I prefer the portrait view for many reasons, and it has become increasingly annoying when my phone adjusts to landscape in the middle of typing an email or whatever simply because I happened to angle my phone one way or another.

[Mrjinglesusa]

There is a Cydia app called Rotation Inhibitor. It is an addon for SBSettings and it works on 3.0. However, it obviously requires a jailbroken iPhone.

Rotation Inhibitor: SBSettings Toggle Allows you to Disable Accelerometer - iPhone Hacks

For non-jailbroken iPhones, there is presently no way to disable landscape mode.