Some innovative companies have announced portable Bluetooth keyboards for the iPhone! (Way to be cutting edge, Apple. Palm had this kind of stuff 10 years ago for their PDAs and smart phones. Yeeesh.)
Oh, but wait- they don't actually work yet. Apple has not released drivers for the iPhone, so consumers can't enjoy this very useful technology unless we hack our phone. I wrote about the need for iPhone keyboards, and the available hacks a while back on my Easy Tech Zealot blog.
I suspect the reason is that Apple doesn't want to cannibalize possible "MacTablet" customers. Truth is, most die-hard Macheads that I know would buy both. I think Apple is missing an opportunity to cement the iPhone as the platform of choice for many users, especially with Android phones hot on their heels.
Google's Android is free, with many different suppliers, phone vendors, and price points. It's hard to compete with free, and even harder to compete with Google. Remember Yahoo, Hotmail, Outlook, Internet Explorer, and MS-Office? Google has supplanted or is rivaling all of those once-leading products. It will take time, but many phone users will choose "cheap and good enough" over "expensive and elegant." Many already have. So, lighten up, Apple. Give us the BT keyboard, already!