My 2xCR123 batteries last close to a week providing all the water I need for drinking/cooking/cleaning during heavy activity. If the scenario you're planning for lasts longer than that then you'll want something more than a straw anyway.

I'm a big fan of the Steripen as well... But, as with everything, you better have a backup in case of failure (bulb, batteries, etc...)

If you are boiling your water, you're in good shape anyway. The Steripen makes it easier to fill up on the move...

Welcome Javelin! I've been thinking about getting a Lifestraw for my urban EDC backpack.

I have a Frontier Straw Filter in my dayhike pack.

I'm curious about the differences between the two. (Off the top, it looks like they both filter down to 0.2 microns, and the Frontier looks smaller and cheaper.) The filter in both packs is intended for short term emergencies only (I also carry microPUR tabs, as well as a bandana to pre-filter) so I don't want anything heavy, bulky or expensive but do want something reasonably effective in an urban environment.

I just wanted to drop and fyi that the Scouts Canada Scout Shop has the Life straw on sale for $21.99 right now. Amazon lists it at $24.99 so it's a bit of a savings.

http://www.scoutshop.ca/eSolution/search...raw&lang=en

And I believe registered members receive an additional percentage off their price on camping gear (I don't recall exactly what the percentage is).