It's been about 24 hours since I've jailbroken my iPhone 4. This is my first jailbreak experience, and while the actual jailbreaking was super easy, the aftermath was a bit confusing. After you jailbreak, you get an icon on your homescreen that launches Cydia, an repository of "packages" that include a vast array of apps that can tweak your phone. It's really up to you to figure out which packages to install, but with a little searching and asking on Twitter, you'll soon be pointed in the right direction.
On the iPhone 3GS and previous iPhone devices, jailbreaking often meant having to deal with a slower device with reduced battery life. The iPhone 4, thanks to the boost in battery capacity and CPU speed, can handle more tweaking than its predecessors. In the last day, I've noticed that my device is slightly slower and more power hungry, but not enough to impact usability.
So what have I done thus far? I've used IntelliScreen to allow me to see email previews right from my lock screen, MyWi to turn the iPhone into a WiFi router, WinterBoard to load themes, SBSettings to enable an easy way to toggle on various system radios, MIM to change the carrier name in the upper left corner, and Five Icon Dock to increase the number of allowed icons in the dock to five. Most of what I've done so far has been to make iOS feel as usable as Android and Windows Mobile, which can do many of the things I mentioned above out of the box (or without rooting/unlocking/HardSPL'ing). I'm looking forward to exploring more of the wonders of jailbreaking over the coming weeks.
Have you jailbroken an iOS device before? If yes, what are some must-have tweaks that have made a big difference in that usability of the device?