If you plan to make year-end donations to a charity, church, synagogue or college, this year's stock-market run-up presents a great opportunity to let Uncle Sam subsidize your gift - twice.

Of course, contributions are deductible if you itemize on your tax return. But when you give away stocks or bonds that have appreciated, you can deduct the full market value of your gift, and you don't have to pay taxes on the investment gains you give away.Say you bought 100 shares of High Tech Inc. at $10 per share, and it's now worth $40 per share. Sell your stock, and the tax bill on the $3,000 gain is $840 if you're in the 28 percent bracket.

But let's say you plan to give your church a $4,000 gift. Give cash and you get a deduction worth $1,120 in the 28 percent bracket - which means the gift really costs you $2,880. Give your shares of stock instead, and you also avoid the $840 tax bill, bringing the cost of your $4,000 gift down to $2,040. (One catch: You must have owned the shares for more than a year to qualify for this break.)

You don't have to give away all your shares. To make a $400 gift, for instance, you could donate just ten shares of a $40 stock.