You are in a situation where you have only the following and you MUST find a way to boil a liter (not necessarily all at once) of water within the next 8 hours.

The environment:

-Plenty of non-drinkable (without boiling) water.
-There are no Brich trees so lets not get in to the whole Birch bark container thing. <img src="/images/graemlins/wink.gif" alt="" /> The area is wooded with, furs, cedars, maples oaks and cottonwoods and shrubbery common to north america.
-Temp is about 80 degrees and high temp for the day is expected to be about 85
-Its about 11am so you have until 7pm to get your water boiled, cooled and drank.
-If you can find a way to stor the water, great, but this is not a requirement. You can boil, cool, drink a 1/3 of a liter three times in that time period if you want, just as long as you have boiled, cooled, and drank one liter of water within 8 hours

Your Gear:

-Lighter, Sparklite, Ferrocerium Rod, Lots of Matches, Vasoline Cotton Balls (yes this is a bit exaggerated... the point is that starting a fire isnt a problem in this scenario)
-High Quality Fixed Blade Knife w/ 5" blade.
-Photon II Flashlight

Okay so basically the way I am trying to set up this scenario is that youre in a typical modern day north american wooded area in the summer. You have a good knife, good firemaking equipment and plenty of good dry tinder, kindling and fuel for the fire. The only way to get drinkable water is to boil it and you have no container in which to boil and/or drink from. How do you improvise in this situation. The time limit prevents you from wating till morning for the morning dew or extracting water from plants in some other way. You MUST boil your water in this scenario so it would seem that you must improvise a container in which to boil it. How do you imporvise such a container???

One last thing... In this scenario there is no trash of any type left behind by humans that is anywhere to be found. So. no you cant say "I'd pick up the soda can left behind by other hikers and use that to boil in".

Does this seems like an impossible situation? I know it's one that I have pondered and I have yet to come up with a "good" solution. Can you carve a bowl out of a log or weave a backet and boil with hot rocks? Remember you only have 8 hours to get a liter of water boiled and cooled.