I hope I'm not breaking any rules or etiquette by making this blatant plug as my first post on these forums, but here goes.
If you're like me, you were very excited when you heard about the iPhone, then very disappointed when you heard the news that it was to be a closed platform with no user-installable applications. To attempt to persuade Apple to reverse this decision, I've created a petition which I plan to deliver to Apple Corporate with as many signatures as possible:
iPhone Third Party Application Support Petition
If you agree, please give it a read and consider signing.