Creating 3D Text in After Effects.
Creating 3D text in After Effects has long been a cottage industry, generating many workarounds and 3rd party plug-ins.
Adding to the parade is one of the big new features in After Effects CS6, the extrusion and material options in the Ray-tracing renderer, which almost requires an Nvidia GPU. Many will benefit from beautiful renders with the new features, though many will get bogged down by requirements, render times, or inadequate features, and turn to older methods surveyed here.
Update: Despite some optimism, in the summer of 2014 Adobe appeared to be leaning heavily on a single 3rd-party app for future 3D. For more and major current tool options, see the above roundup and AEP's Comparing 3D type options for After Effects, where you'll find that Ray-traced 3D was declared (walking) dead by Adobe. Ray-traced 3D still works, but it will be retired in some future release.