Hello I am new here I have the iPhone 3G and installed stuff from cydia the phone seem to become reallllyyy laggy so what I did to keep that from happening is not to install updates from cydia just download ultrasn0w and download everything from the app store. This isn't for people who like to customizing the iPhone or want the apps from cydia or icy it for people who just want the iPhone for the network they are on for me T-Mobile. So that is what I did to keep it from lagging if you do post back and give your results. Oh and I figure out that T-Mobile will block your access to the internet if you don't have a data plan.