Pedal Power Hydraulic Log Splitter

It's hard to beat the maul. See:

www.pssurvival.com/ps/Firewood/Splitting_Firewood_1981.pdf

There are hand powered versions:

http://www.harborfreight.com/10-ton-hydraulic-log-splitter-67090.html

Maybe you could modify it to use hands and feet a la NordicTrack

https://www.nordictrack.com/fitness/en/NordicTrack/Skiers/nordictrack-classic-pro-skier

(and get in shape for cross country skiing at the same time)

and foot powered hydraulic piston pumps:

http://www.enerpac.com/en/news/lightweight-hydraulic-foot-pump

You could attach two to get a "Stairmaster" hydraulic pump similar to treadle water pumps:

http://www.kickstart.org/products/super-moneymaker/

http://treadlepump.blogspot.com/