I have a couple year old set of Black Diamond Spires that are useable, though not my idea of ideal. Went to BDs website a while back to shop around and noticed they have some 2012 poles on sale for 33% off! Picked up a set of Z-poles in 130cm and saved $45! Just checked and there are still some Z-poles on sale, as well as the Carbon Corks and others. Guess they are liquidating last years model stock...
Anyhoo, just wanted to give a heads up to check out Black Diamonds website if you are in the market for trekking poles, you may find a deal!