The Digital Photography Blog: all you need to know about digital cameras and photography
Top 10 Digital Photography Tips is a great article that shares a number of tips that you may not have considered before including:
'Sunglasses Polarizing Filter
What's that you say? Your digital camera can't accommodate filters. Don't despair. I've been using this trick for years with my point-and-shoot cameras. If you have a pair of quality sunglasses, then simply take them off and use them as your polarizing filter. Place the glasses as close to the camera lens as possible, then check their position in the LCD viewfinder to make sure you don't have the rims in the shot.'