You used to be able to hit print but now that's disabled. That's what the conventional old method was.
Print works, but only on shorter threads. I'm not sure what the limit is at, but it's still handy for searching through shorter threads. You can also append "
;wap", "
;wap2" and "
;imode" at the end of URLs for a lightweight text only link, but it only does one thread page at a time.