kosso
thinks
the left to right thing doesn't 'flow' as nicely as up and down. We're less used to it.
agrees
UKStevieB
says
many Twitter fans prefer to use www.plurk.com/m/ for its more traditional interface 
kosso
likes
that more 
cheers!
cheers!
jcass
says
try using arrow keys, with the mouse I never control the scrolling