Anyone making a contribution to a qualified charity, that is, 501(c)(3) organizations between August 28 and December 31, 2005 may deduct 100% of those contributions from their Federal Income tax regardless of what those contributions amount to.
This is a suspension of limitations on charitable contributions for relief efforts relating to Hurricane Katrina. However, gifts do not have to relate to hurricane relief. There is no minimum or maximum gift amount to qualify. When you do your taxes remember that all your gifts, not only those for hurricane relief, but those to your church (assuming it is a 501(c)(3) organization), Jews for Jesus or any other such organization are completely deductible if they were given during the specified time.