http://www.kk.org/cooltools/archives/003297.php
Thanks to Kevin Kelly - Cool Tools
http://shop.ebay.com/items/_W0QQ_nkwZtanklessQ20waterQ20heaterQQ_armrsZ1QQ_fromZR40QQ_mdoZ
I thought maybe you guys would be interested in this.
Bosch makes a LP/NG tankless that needs no electrical hook up it has a micro water wheel that provides all the electric the igniter needs to light the burner. So as long as you have water flow you have hot water.
w* to the forum. We have the earlier model of that Bosch - the HX125 LP. We like it. It is in a more permanent category allowing about 2 fixtures to run at once and around $600. I don't know if they make a smaller one though. It has been superseded though.
There is also the Ecco Temp L10 (deluxe model) on sale at Amazon for about $240.
Specs seem to elude that it may be more appropriate for cabin/temp res use than the L5.
Though the L5 has a lower required psi (20 psi vs 30 psi) which could make a difference if "gravity feed" is an issue.