AA is currently offering 20 miles per $1 donated (for over $25 donations) to their charity partner, the Cure/Komen.
From a tax perspective, note that the miles have a value assigned by AA:
For charitable deduction purposes, each mile is valued at 2.75 cents per mile if fewer than 6,000 miles are awarded and 2.5 cents per mile if 6,000 or more miles are awarded.
Link
The value of the points applies to IRS rules that you cannot deduct a donation if you receive something in exchange for it. EG if you paid $100 to attend charity dinner, and the dinner was valued at $50 you could claim $50 as a donation for your tax deductions.
From a tax perspective, note that the miles have a value assigned by AA:
For charitable deduction purposes, each mile is valued at 2.75 cents per mile if fewer than 6,000 miles are awarded and 2.5 cents per mile if 6,000 or more miles are awarded.
Link
The value of the points applies to IRS rules that you cannot deduct a donation if you receive something in exchange for it. EG if you paid $100 to attend charity dinner, and the dinner was valued at $50 you could claim $50 as a donation for your tax deductions.