So does applying the parking brake!  You can apply the parking brake
while keeping the release button pushed to keep it from locking on and
prevent a great deal of wheel spin.  Modulate the force of your pull
until you get out of your jam.  I've used this trick many times, it
works even when one wheel is on ice and the other on pavement.

--
Stuart MacMillan
Seattle

'84 Vanagon Westfalia w/2.1
'65 MGB (Daily driver since 1969)
'74 MGB GT (Restoring sloooowly)

Assisting on Restoration (and spending OPM):
'72 MGB GT (Daughter's)
'64 MGB (Son's)

Stripped and gone but their parts live on:
'68 MGB, '73 MGB, '67 MGB GT