Help with iPhone lag

[Sindy Mendler]

Hi there. My iPhone is a black iPhone 4 with version 4.0.2 with no jailbreak. Recently my phone is really LAGGY and when I want to load something or watch a particular show, it loads like 3 times slower than normal which really pisses me off.Just wanna ask. Does jailbreaking your phone makes it even more lag? If I update my phone to IOS5, will it load faster?
How do I jailbreak my phone? When I want to update, what should I do to make sure all the data in my phone like photos etc does not gets lost?

Thank you for your help I really need it!

 

[iphonewarrior]

Wow! You're on an old firmware!

Jailbreaking does make your phone lag slightly, but you can improve your user experience by installing an app called FakeClockUp. This app accelerates your GUI, quite clever really.

There is a jailbreak for iOS 5, but it's tethered. There is currently not ETA on an un-tethered jailbreak.

If you do decide to update, backup your phone, backup your pictures, contacts etc etc and update your OS. iOS 5 runs great on my iPhone 4.

 

[RoofMonkey]

You may have already tried this, but have you powered your device off recently? You can also try holding both the sleep and home button at the same time, ignore the slide to power off. Keep holding them both until you see the Apple logo, then release both. This is a hard reset / reboot of the device. No data will be lost, but it will take it a little longer to boot backup to the normal screen.