According to this space.com story today:

http://www.space.com/news/moon_mars_040729.html

NASA's Human and Robotic Technology group has just issued a "Broad
Agency Announcement", which is basically a roadmap of requests put out
to big and small aerospace firms, universities, and non-profit groups to
come up with creative concepts.

Notice to NASA must be given by August 13th, with a full proposal by
September 24th.

The areas they're looking for proposals in:

* artificial gravity - structural concepts for artificial gravity
systems, including long deployable trusses and tethers that can hold
together while spinning through interplanetary space. Such systems
should also include methods to control rotation rate and structural
dynamics.

* inflatables - concepts for inflatable truss elements that
self-rigidize to enable the in-space assembly of large platforms, and
inflatable habitats with integral radiation shielding, impact shielding,
thermal management, and equipment to keep tabs of the overall health of
the inflatable hardware.

* Space resources! - excavation, extraction, collection, beneficiation
technologies for lunar and/or Martian resources, autonomous or
tele-operated robotic technologies for surface facility assembly and
maintenance; and, technologies for off-Earth creation of solar
photovoltaic systems or other energy systems.

More information on this is available here, including a Word file with
details on these and other research areas of interest:
http://www.exploration.nasa.gov/webcast.html

I believe John Mankins, who used to head up NASA's space solar power
program, is in charge of this - note the inclusion of several
technologies very relevant to space solar power in the request!

Arthur Smith