I've never heard of this being done. If a viewer wants to visit http://www.itypedallallthisin.com/ he would type it into his browser address bar instead. Why do you want him to type it into your input box?
I expect PHP or possibly javascript could do it. The submit button would be set up as a hyperlink with no url initially but with a request for anything typed in an input box.
You have to consider that viewers might mis-type an address or just type text, so the PHP would have to be set up to return to the original form if the text did not conform to a url (similar to forms rejecting email addresses if not in the correct format or input boxes for required fields not being completed).
It's beyond my capabilities, so ask on the PHP board.
Code downloaded to my PC will be deleted in due course.
WIN7; IE9, Firefox, Opera, Chrome and Safari for Windows; screen resolution usually 1366*768.
Also IE6 on W98 with 800*600 and IE8 on Vista 1440*900.