(Un)checking a whole set of checkboxes at once

Subject Date From Size
Happy new year! Jan 1, 2010 00:03am Drew Barrimore 1.6Kb
What’s that great IT book publisher again? Jan 1, 2010 11:25am David McClintock 2.3Kb
You gotta check this out… Jan 2, 2010 02:15pm Julianne Moore 4.2Kb