Here's a neat solution: the Personal Battery Caddy. Cells snap in and out of these plastic holders in either direction, with both terminals safely recessed. They are available for AAA, AA, C, D, 9-volt, or 123A cells, and in combination units to hold several types. Since they come in a variety of colors (including glow-in-the-dark), you could color-code your rechargeables -- green for good and red for dead, say. They range in price from $5 to $14, direct from www.personalbatterycaddy.com.