I hope this isn't dumb but what does "s/Webkit/moz" mean? To answer the poster above you, it would work by adding "-moz-propertyname" not removing the "-webkit" stuff. Each browser will ignore the proprietary prefix that doesn't apply to them and then apply the CSS to any style that is prefixed for them or the official implementation. So you can put prefixes for all vendors in your rules and the browser will choose the one that applies while safely ignoring the rest. Just make sure to add the "official" non-prefixed version last so that future browsers or those who implement the spec completely today can render the final version of their implementation of the specific CSS style instead of the half baked proprietary one.

I'd add that vendor prefixes are one of the best reasons to use LESS (or SASS or SCSS, I just prefer LESS). Write one mixin (6 lines of code if you line break between each property) and you've just saved yourself countless keystrokes.