Requires iOS 5 or higher
With WebOffline you can simply download a web page and view it while you aren't connected to a network (WiFi/3G), directly from Safari.
To Use: press the action button in the Safari toolbar and choose the new option for `Save for Offline`. Page will save, then you can view it from Bookmarks > Saved Pages. Toolbar button option can be configured from the Settings app.
See all the Screenshots below