[xmonad] Spawn all new windows into slave pane?

I was wondering if it was possible to set xmonad.hs to spawn all new windows as slaves, the current behaviour I have, where the new window replaces the currently focused one, really disrupts my workflow (like the commas in this sentence). Here's a link to its current iteration if anyone needs to take a peak. http://github.com/eclectricsheep/dotfiles/blob/c4d7b53a2e026e88e08c39a382edf... Thanks! -Eclectric Sheep