This is a geeky stuff, but recently discovered that my left hand is become quiet uncomfortable with the left Windows key, which I use for program launching in i3. I also realized that switching the left Alt and left Windows key would be probably the best solution. I found a simple solution through Xmodmap, which I like because it's distro independent.
I added these lines to my ~/.Xmodmap files:
keycode 14 = Alt_L keycode 93 = Super_L remove Mod1 = Alt_L remove Mod4 = Super_L add Mod1 = Super_L add Mod4 = Alt_L
The keycode means the position of the two keys in the keymap table. You can find this with the utility, called xev.
Then we remove the default Mod definition of the left Alt and Windows keys, and last we switch it.
Thanks to my nice keyboard, I will be able to switch the physical keys too. :)