Just wanted to give a heads up - Woot.com has a Uniden 5.8Ghz cordless phone system for sale today that includes a waterproof handset, which should be perfect for poolside. $49.99 + $5 shipping. I bought me one!
disclaimer - I'm not employed or receive any compensation of any kind from woot.com for any referrals. Just trying to help my fellow pool owners out.