How to use input widget in Tkinter

This seems like a very general question, but here is a website that has great granularity, and here is a very simple general example:

import Tkinter as tk

class application:
    def __init__(self,window):
        """ Initalize the Application """
        self.myentrybox = tk.Entry(window)
        self.myentrybox.pack()
        self.myentrybox.insert(0,"some default value")
        self.myentrybox.bind("<Return>",self.Enter)

    def Enter(self,event):
        """ Someone Pressed Enter """
        print "You entered >> %s" % (self.myentrybox.get())

root=tk.Tk()
myapp = application(root)
root.mainloop()

Hope you can extrapolate what you need to know ...