is there a way to restore iPhone back to original state with just 'installer' present?

after finally jailbreaking my phone and playing around with multiple applications installs (via iBrickr, Installer, etc.) i feel like i got a lot of junk on my phone. so i'm wondering how can i go back to original files content.

also i've noticed that there are couple of ways i can install apps, one via installer another via iBrickr. which way is most preferred?


thanks!