President Obama has signed into law legislation passed by Congress designed to encourage Americans to contribute cash to charities that help with emergency aid and rebuilding efforts in Haiti.

The new law allows taxpayers to make charitable contributions of cash to Haiti relief programs before March 1, 2010, and claim those contributions on their 2009 tax returns.

Without the new law, taxpayers would have to wait until next year's filing season to claim a tax deduction for such Haiti-related contributions.

The measure is similar to a law enacted in 2005 following the Asian tsunamis.

The new law allows taxpayers to use, as documentation of a contribution to a relief effort for Haiti, a telephone bill that shows the name of the recipient charity, the date of the contribution, and the amount of the gift. Donors have contributed millions of dollars via text messages to charities involved with Haiti relief efforts.

Usually, donors must obtain and keep a bank record (including canceled checks or credit card statements) or a written acknowledgment from a charity as a proper record of a cash contribution. Written records prepared by donors (such as check registers or personal notations) are not sufficient.