Fusion360
Fusion 360 brings Industrial and mechanical design together in a single easy-to-use design tool. Start by using simple push pull commands to get just the right shape, or take a short-cut by bringing in one of your existing or scanned models. Then add the detail needed to make your design manufacturable.
Fusion 360 is a web based 3D CAD tool with builtin support for sharing designs.
Free for personal use during Beta testing, Fusion 360 is expected to have a $25/month subscriptin cost at launch.