The difficulty with patents in design is that as a designer you are trained to boil a product down as much as possible, remove as much as possible and simplify. The problem comes when you come up with the (near) perfect design it's so simple that everyone slaps their collective heads and say why didn't we do this before? But the truth is, no body did do it before because the inituative response is trained by years of doing things the same way (often the wrong way). Many obvious user interface designs need to be learned because they are actually counter to what we have learned to do over time.
(case in point, sliding fingers up on a track pad to scroll up? Made perfect sence when it was a wheel on a mouse but absolutely no sence for a track pad since you are directly manipulating a document by grabbing it. But I can't get used to a reverse trackpad so switched it off!)
Patents are put in place to protect innovation but if the job of a designer is to simplify, should this not also be protected? You could argue that dysons vacume was 'obvious'. He walked in to a powder coating factory where his ball barrow frames were being coated and they were using a cyclonic vacuume to collect the unused powder. Was this head slappingly obvious to any one who had seen the technology NOW? Yes it is. Had any done it? NO. Applying existing ideas Uin a novel way is grounds for a patent.
I see the value of these small user interface features, I think that's why I have rubbed some up the wrong way as I apreciate many don't. Since we interact with UI elements directly, i see them as just as inportant as componants, not 'just' software. No one had developed the iPhones multitouch elements in to a commercial product before 2007, just like no one had developed the cyclonic vacuume to a commercial product before dyson, and that should be enough.
(this post is not specifically defending slide to unlock patents. Although I think it was important as a small percentage of hundreds of elements that make the iPhone what it is, I have been baffled by the clout that patent has been given).