You could try to write on the canvas using a small font. Maybe something like this:
Other than that I don't know of anything that would work.
canvas.text((10,y), u"Text goes here", font="default")
#You have to increase y each time to avoid writing on top of the previous line
EDIT:There may be a "long way around": having a menu to switch between the two.
In the example above, you can use the menu to switch between canvas and text. To illustrate that it works, every time you select "text", "G" will be printed. Just adapt it to your needs.
import appuifw, e32
from graphics import *
from key_codes import *
#The keyboard class I used can be found here (at "Method 2"):http://wiki.forum.nokia.com/index.php/How_to_handle_keypress_easily
appuifw.app.menu=[(u"Canvas", showc), (u"Text", showt)]
bg.text((30,30), u"Something", font="title")