From desktop to laptop to tablet to nothing. It's vapourware at this point, but IMSI/Design will have its TurboSite software ready when Google ships its Glass eyeware later this year. I'll quote the press release directly, which describes a scenario:
Simulated image of Glass eyeware (left) and image seen by user (right)
A user -- carrying nothing but wearing the smart device glasses and running TurboSite -- will see building plans directly in front of them. GPS will track their movement through a drawing.
The built-in eye glass camera will let them take pictures and record video and TurboSite will automatically insert these into a markup layer at the exact location.
When the field report is finished, it is automatically printed for distribution or instantly sent electronically to the entire design and construction team.
Google Glass runs Android, of course. And TurboSite runs on Android, too. Any other CAD vendors working on Google Glass implementations of their software?