Avg stay for users on a new website = 1 minute and 49 seconds in that time that the website didn't fulfill their needs,users left.
For most computing tasks the threshold of frustration is about 10 seconds.
Users prefer menus that present at least five no more than 20 links without having to "Scroll".
Three-click rule states that users will not stay onsite if it takes more than three clicks to access the information they need. Generally, No need for more than 3 nested levels with 3 to maximal 7 items per level.
* Source: Yale Institute Web Style Guide 2nd Edition
drawing on the screen,
access to the keyboard and mouse.
Services have worked to combine all of these into a more familiar interface that adopts the appearance of an operating system and does NOT require page reloading. Example: www.280slides.com
GUI Builders: Software tools that simplify the creation of GUIs. These allow designers to arrange widgets using a drag-and-drop editors. Typically XML us used to export GUI builder files. (New Yahoo Site)