3D to Letterpress - Experimenting with 3D text via the CSS3 text-shadow property in combination with CSS3 transitions to transition the 3D text to a true inset/letterpress text effect with text-shadow.

index.haml

%ul
  %li
    %a{:title => @title, :href => "#"} Home
  %li
    %a{:title => @title, :href => "#"} About
  %li
    %a{:title => @title, :href => "#"} Contact

style.sass

@import "compass"
body
  font-size: 1em
  font-family: "HelveticaNeue-Light", "Helvetica Neue Light", "Helvetica Neue", Helvetica, Arial, "Lucida Grande", sans-serif
  background: #f6f6f6
  letter-spacing: .15em
  text-align: center
ul
  margin: 0
  padding: 0
li
  list-style-type: none
  font-size: 2em
  display: inline-block
  margin: 0 1.5em
  padding: 1em 1em
a
  background-color: rgba(0, 0, 0, 0.1)
  color: transparent
  text-decoration: none
  font-size: 3.5em
  font-weight: bold
  -webkit-transition: all .25s ease-in-out .1s
  -moz-transition: all .25s ease-in-out .1s
  -o-transition: all .25s ease-in-out .1s
  -ms-transition: all .25s ease-in-out .1s
  transition: all .25s ease-in-out .1s
  background-clip: text
  -moz-background-clip: text
  -webkit-background-clip: text
  text-shadow: 0 1px 0 #ddd, 0 2px 0 #c9c9c9, 0 3px 0 #bbb, 0 4px 0 #b9b9b9, 0 5px 0 #aaa, 0 6px 1px rgba(0,0,0,.1), 0 0 5px rgba(0,0,0,.1), 0 1px 3px rgba(0,0,0,.3), 0 3px 5px rgba(0,0,0,.2), 0 5px 10px rgba(0,0,0,.25), 0 10px 10px rgba(0,0,0,.2), 0 20px 20px rgba(0,0,0,.15)
  &:hover
    background-color: #999
    color: transparent
    text-shadow: rgba(255,255,255,0.75) 0px 2px 3px