Thanks, I've checked out the Lensmate site and like the look of the 52mm. I'll return my Canon 58mm tube to the dealer and buy the Lensmate through the Internet. It just means I'll have to change my filter to a smaller size.
I've also discovered a hood made by Hoodman for the G3 that costs about $30 Cdn. I'll try it at the dealers to see if it works well with the articulated LCD on the G3.