Until now I was using synclient TouchpadOff=1 in my .xinitrc, but I was getting odd results when using the keyboard mouse buttons. It turns out oddly the lower left area of my touchpad was infrequently active and messing things up.
Replacing synclient with xinput set-prop 11 172 0 fixed it.
I obtained the touchpad ID with xinput list and the command with xinput -list-props 11
$ xinput list
⎡ Virtual core pointer id=2 [master pointer (3)]
⎜ ↳ Virtual core XTEST pointer id=4 [slave pointer (2)]
⎜ ↳ Logitech Wireless Mouse id=9 [slave pointer (2)]
⎜ ↳ TPPS/2 IBM TrackPoint id=12 [slave pointer (2)]
⎣ Virtual core keyboard id=3 [master keyboard (2)]
↳ Virtual core XTEST keyboard id=5 [slave keyboard (3)]
↳ Power Button id=6 [slave keyboard (3)]
↳ Video Bus id=7 [slave keyboard (3)]
↳ Sleep Button id=8 [slave keyboard (3)]
↳ AT Translated Set 2 keyboard id=10 [slave keyboard (3)]
↳ ThinkPad Extra Buttons id=13 [slave keyboard (3)]
↳ Logitech Wireless Mouse id=14 [slave keyboard (3)]
∼ SynPS/2 Synaptics TouchPad id=11 [floating slave]
$ xinput -list-props 11
Device 'SynPS/2 Synaptics TouchPad':
Device Enabled (172): 1
...
$ xinput set-prop 11 172 0
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