Darrel Morman, a mechanical drafter, sends us a trick to group objects quickly.

"You can create 3D blocks rapidly and easily by using Ctrl+Shift+C to copy several of your 3D objects in an assembly or group with a base point (soon to be the block insertion point), then Ctrl+Shift+V to paste the selected group of 3D objects into your drawing at the desired insertion point. This allows groups to be placed, and if needed, exploded. After exploding, objects retain 3D solid properties and can be moved individually. Make sure to purge blocks often; AutoCAD will create a random name each time a block is made, and those blocks will clutter the drawing if they are not purged."

Notes from Cadalyst Tip Patrol: This can be done with 2D objects as well as 3D solids. In fact, it can be done with any object in AutoCAD. Select your objects, then press Ctrl+Shift+C to copy the objects to the Windows clipboard, and provide a selection point. If you don't use the Shift key, Ctrl+C will just copy the objects to the clipboard. Ctrl+V will paste them, but Ctrl+Shift+V will paste them as a block. This makes copying objects very quick and easy, especially if you are copying from one drawing to another.