Firstly this is not my own original idea! My source is Macosxhints. They posted this hint a few months ago before I was an iPhone owner but I made a careful note of the hint because I knew I would utilise it.
Basically I can take any file on my laptop and save it to my iBooks now with 2 clicks and a sync. This is how I did it.
1. Create an alias of itunes in the applications folder.
(for those who get lost on step 1 check out image below:
Applications > iTunes, Right click on iTunes > Make Alias)
2. Drag this alias to ~/Library/PDF Services
[that is the system one (for TBC teachers it is our Teacher Build) not the user!].
3. If you have not yet downloaded the iBooks app from iTunes you will be prompted to do it the first time you attempt to sync your iBooks to your device. It is a free app.
DONE - It is that easy to set up!
Now when you're browsing the web or viewing documents and you decide you want to read them later on your iPhone or iPod touch or iPad just hit Print, click the PDF button on the bottom left corner and choose iTunes alias.
iTunes will launch and recieve the PDF.
To actually get the file on your device don't forget you will need to "sync your device" and then the file will be sitting in your iBooks app.
If you have another way that you think is better please leave me a comment, I know there is more than one way to skin a cat so to speak so I would love to hear anyone else's great ideas/handy hints.