Here's some information about how to stream your iTunes library to an iOS device. Yesterday I upgraded our iPad to iOS 4.3.1 and I was really looking forward to being able to stream anything from my iTunes library to the iPad. Much easier than synching.
Unfortunately it is not as straightforward as I thought it would be with Apple. There are no instructions to be found on the Apple website. But I found this website that describes the different steps.
You will need an iOS device running 4.3.1 and a computer running iTunes 10.2.1 and of course a WiFi network. And of course the computer with the shared library needs to be running iTunes.
I had already switched on Home Sharing on my MacBook to share between two Macs. But there is a caveat. Your password for your Apple ID needs to be at least 8 characters. You might have to change the password for your Apple ID.
The iPod app on your iOS device won't show videos from your iTunes library. You have to use the video app on your iOS device for that.
I have just watched a program I downloaded with Get iPlayer automator. That's a really cool app for the Mac. It will download the stream from the iPlayer website and converts it to mp4 and adds it to your iTunes library.