If you have gimp, there are a couple ways of doing HDR there as well. For quick and dirty stuff, I found the exposure blend plugin [1] to work pretty decently. For more complicated stuff, doing the exposure masking yourself [2] also leads to real good results. As far as speed, there are a few apps out there that will let you bracket and do an automatic hdr sequence out there if you have a phone with an IR diode, yeah it means fumbling with two devices, but the results would almost certainly be well worth it.

[1] http://tir.astro.utoledo.edu/jdsmith/code/exposure_blend.php

[2] http://www.instructables.com/id/HDR-photos-with-the-GIMP/