Saved myself both time and money replacing my iPhone 4s battery through BattDepot. Shipping was within 24 hours, battery replaced in 10 mins, phone back to work! You get all the supplies and tools needed, the website provides step by step instructions - well worth trying!
Saved me over $400! Didn't even realize you can replace a screen until I saw this site. Really fast shipping, great price and very simple to install. Highly recommended if you have a cracked laptop screen.