Thanks Chris Bray. I now have some extra functionality in Safari. I'm particularly glad to have Diigo and Evernote bookmarklets for saving links and notes without the rigmarole of jumping between apps. I'd be interested to see a bookmarklet that opens Evernote from Safari or that can open the Twitter app from Safari. Might need to do some more research.
In the illustration you can see them listed on the bookmark bar which can be turned on from the Settings App.