Dear Allin,

This is really a very nice (and useful) feature. I have some small suggestions to improve it. This function is a very common feature in Internet browsers like Firefox, Safari and Chrome. In all of them (Mac versions!) the "zoom function" is activated by pressing "Command" + "+" (to increase), "Command" + "-" (to decrease) and "Command" + "0" (to restore the original size). On Windows just replace "Command" for "Ctrl".

Just for curiosity, I checked the maximum levels of each navigator:

Firefox
max increase: 8
min increase: 5

Safari
max increase: 7
min increase: 4

Chrome
max increase: 9
min increase: 6

I hope this helps ;-)

Best regards,
Henrique Andrade