Smart Phone Batteries

My smart phone and ipod batteries run out quickly because I use them like crazy. Well actually my son uses my ipod now for games but I am so dependent on my smart phone for just about anything - to check emails, browse the news, play games, facebooking, sending text messages, storing database of addresses and phone numbers and a lot more. I need a new battery pack for my ipod touch and I've been looking for online stores that carry them. I saw an online store that sells replacement batteries like samsung mobile batteries and a lot more, so its my best bet to get the battery pack that I need.