File Uploads
Watir now has a mechanism to support file uploads. Use the file_field
method. Run and view the Ruby source in filefield_test.rb
in the unit tests folder for usage.
If you are given the option to upload a file from a web page, this is the dialog that will be shown. It would normally appear when using the <input type=file> html tag
See http://msdn2.microsoft.com/en-us/library/ms535263.aspx

Simple example (file image.png should be in the root directory of C: drive):
ie.goto "tinypic.com"
ie.file_field(:id, "the_file").set("C:\\image.png")