Matrox WYSIWYG Plug-In For Adobe After Effects
The Matrox Pahelia series video cards offer a WYSIWYG (What You See Is What You Get) video output plug-in for Adobe After Effects. This plug-in will allow you to preview your work in After Effect through Composite or S-Video output on the fly. I own the Matrox Pahelia 128 Card and the video output feature for After Fx makes life so much easier.
Once you have the plug-in installed you can set your preferences by going to Edit > Preferences > Matrox WYSIWYG Plug-In.
On a side note the WYSIWYG Plug-In will also work for Photoshop, Premiere, Combustion, 3DS Max and LightWave.