Chris Zurbrigg shows how useful, and well planned his Blue Pencil tool for Maya which is a grease pencil utility that will allow you draw directly in the Maya viewport… However, Blue Pencil is so much more than that. Blue Pencil will allow you to draw thumbnails for rough blocking reference (either on the viewport, or in a handy smaller floating window) which is actually stored in the Maya Scene file. You are also able to retime the thumbnails easily with the retime tool. Blue Pencil really looks like an indispensable tool for animators!
Check out the Blue Pencil Sketchpad for Maya on Chris Zurbrigg’s site.
Blue Pencil is a plugin for Maya that brings 2D drawing to the 3D viewport and it is built to be a multi-purpose tool that can be used to Grease Pencil, planning, annotation and illustration, create animation thumbnails, rough blocking and arc tracking, Model layout and topology planning, Shot review tool and also Tutorials and screen-casting. Blue Pencil looks really great as well with an intuitive and familiar interface that looks like a tiny photoshop pallet right inside of Maya and includes pressure sensitivity and brush control setting panels as well.
Blue Pencil is currently in Beta form, and will be available soon for Maya versions on Windows, Windows 64, and Mac OS X