I know I can't be the only person who uses their iPhone in bed, specifically to read news, books, and various social networks; because of this I end up using applications that allow me to disable landscape mode because if you have tried this you know how frustrating it is to turn over to your side and suddenly the screen flips and it's impossible to read.
Certain wonderful apps like Stanza (e-reader), Byline (RSS Reader / Google Reader Sync), and Tweetie provide this option. I love them for it.
Some apps do not provide this functionality however (Facebook, NetNewsWire, and even Safari) and I hate them for it. I absolutely can't stand using an application which frustrates me in bed. Maybe I'm crazy.
or
Maybe developers should offer this simple switch in their options to turn this off. It may just be that I'm the only person yelling about this but I know other users get frustrated by this as well, it's simply overlooked at times.
So, join me in asking developers to kindly provide this option for us. I'm looking at Apple as well, Safari is a huge pain in the ass while laying in bed.
On a serious note, I agree 100%. There are lots of time where disabling rotation would be useful: in bed, in a small plane, or anything else super jostling.
Maybe the ability to lock the perspective, but also switch in manually.