Sky command has so far been illegal because the FCC considers the path from 
HF back to the hand-held (or mobile), which is on 2 meters, to be part of 
the control of the HF radio. Since this is on 2 meters, and control must be 
on 220 or above, it was not allowed. However it would appear that is about 
to change. WT Docket No. 04-140 addresses this (and other changes) and in
it, the FCC states:

"Because we have no basis to conclude that auxiliary stations transmitting 
on the 2 m band would cause harmful interference or that user coordination 
would not be possible, we believe that Kenwood's proposed rule change will 
be consistent with our flexible-use policy in the amateur service."

See
http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-04-79A1.pdf

Also see
http://www.arrl.org/arrlletter/04/0416/   ,
the ARRL Letter.

Satellite  frequencies and some others are excluded.

Comments are due by June 15.

Don't worry about what people think; they don't do it very often.

Steve, K8SP