Hi Sumsum,
Example programs that use timed loops can be found in the Help>>Find Examples...>>Toolkits and Modules>>Real-Time folder, but timed loops are generally only used for specific Real-Time applications.
As far as the difference between the 'Wait' and the 'Time Delay' vi's, they are essentially the same in terms of their basic functionality. The 'Time Delay' vi is an express vi that has a dialog box and error input and output associated with it, so it is easier to use but utilizes more resources.
Hope this helps.
Regards,
Stephen S.
National Instruments
Applications Engineering