From #git today:

 epitron> i just found out that "git clone --depth=1" lets you pull
          and push, and be backfilled whenever you feel like... can i
          make --depth=1 a default somehow?
 epitron> i couldn't find a "depth" option in the git config settings
 epitron> (i tried using an alias, but i ran into a project with a ton
          of submodules -- github.com/servo/servo -- and i'd like to
          do shallow checkouts of those)
 epitron> (41 submodules, to be precise)
jrnieder> epitron: that sounds like a good feature request --- I
          wonder if 'git clone --recurse-submodules --depth=1' should
          just propagate the depth
 epitron> ooo, that's a good idea
 epitron> lessee
jrnieder> should != does, here :)
 epitron> yeah. :\
 epitron> sad