To answer your updated question...Sure, you can do whatever you want in terms of send requests and receiving data.
It's all about how you implement your server code to handle it. Write a URL that has data on the query string use a GET request (browser purposes), then handle the creating of whatever it is you want to create on the server end.
This is of course breaking HTTP specifications as many people here have quoted.
You can even go as far as making an AJAX request that uses POST with some data in the body as well as the query string and handle whatever you need to do in the server end.
Again, submitting data to the server is possible using a GET
request and it will be visible by the address bar. You may choose to use that data however you wish on your server code and its up to you whether you want to abide by HTTP specs or not.
EDIT
Also, what kind of data are you talking about? Do you want to send a file through the address bar? I don't remember exactly what the length limit for the URL/Query string is but I'm sure binary data wouldn't play nice with it...