Developing online tools using Silverlight

I like to discuss projects/ideas people came up for Silverlight to design/development on online tools. Mainly internets in following two features Silverlight standout from other products

  1. Develop multithreaded application run in internet browser.
  2. Able to read/write to local files in computer using Open/Save dialog box.

Is silverlgith will be better choice to develop some of the front end functionality allow to do some of the work on client side by reducing server load (For example, on a image upload event we can check image size, dimension and then may be auto resize it before upload it to the server).