Previously jailbreaking your iPhone looked like a colossal pain in the tuchus. Why would you even want do that, especially as iPhone functionality has increased with every iteration of the firmware?
The short answer is there are things these ‘magical devices’ still doesn’t do, or rather is allowed to do, even though the capability is often obviously there.
Want some proof? Two words: Internet tethering, the ability to use your iPhone’s 3G serice as a Wi-Fi hotspot. It’s allowed in other countries, but not in the good ole U.S. of A.
The reality is the Spirit jailbreak, is horrifically simple on the iPhone and iPad. It takes about two minutes on average. So really, why wouldn’t you jailbreak?
A jailbroken iDevice gives you access to some cool Apps that are just not available through the iTunes App Store, but through Cydia and Installer, both of which are accessible through jailbroken iPhones.
Below is a list of Apps we think are worthy of jailbreakng your iPhone (this is update list compare to our prio reasons to jailbreak).
While being sheer opinion, we based our list on two main criteria:
The Apps are not available in the App Store, either having been removed or are never gonna show up.
The Apps close a gap in iPhone functionality and can be used on a regular basis. After all lots of apps are cool, but will you use them? We use these.
Also, all the below work on the iPhone and iPad both. This is our biased list, if you have favorites we missed please post them in the comments.
Must Have Utilities:
Cydia
Cost: None
Brief Description: Allows user browse and download applications for a jailbroken iPhone, iPod Touch or iPad.
Basically, this is an App Store for jailbroken iDevices. If you jailbreak your device, you use Cydia to look for and buy apps.
Addexchange
Cost: None
Brief Description: Adds up to 3 more Microsoft Exchange accounts
Alternate choice: MultiExchange
Backgrounder
Cost: None
Brief Description: Allows you to run an app in the background whilst running another, great for Pandora and IMing. Not quite multitasking, but it’ll do, pig.
FakeCarrier
Cost: None
Brief Description: Lets you change what your carrier is called, for some ungodly reason. You must really have to hate AT&T a lot.
Alternate choice: MakeItMine
SBSettings
Cost: None
Brief Description: Allows quick touch on and off for basic functions; wifi, bluetooth etc, w/o having to go thru settings, just swipe the status bar at the top of your screen. No icon!
MyWi
Cost: 9.99
Brief Description: Cannot do without this one, big help on vacations if you have a laptop and need Wi-F on the go,
Quick Dismiss
Cost: None
Brief Description: Allows the user to simply tap the menu/home button to dismiss alerts by simply clicking the menu button. No icon.
Respring
Cost: None
Brief Description: This is really for the developer and unnecessary for anyone else. It lets you instantly ‘respring’ your springboard. If that made no sense to you; then you don’t need it. Most apps have a respring notice when you install them via Cydia.
Rotation Inhibitor
Cost: None
Brief Description: Allows enabling/disabling rotation from SBSettings, good for iPhone, but you don’t really need it on the iPad as it has that switch.
App Organization and management:
Categories
Cost: None
Brief Description: This works on ipad, but in iphone style, free alternative to Infiniboard. Basically you can arrange all your apps into folders, so you don’t have eight pages of apps. You know what’s like is coming to 4.0 OS.
MultiIconMover
Cost: None
Brief Description: You can to go into the normal “wiggle” move mode, just tap on the icons you would like to move. When you tap on an icon a check mark will appear on it (you can tap the icon again to remove the check mark). You can then scroll to the page on your SpringBoard in which you would like to move the icons and tap the Home Button. This will move the selected icons to that page on your SpringBoard. Just tap the Home Button again to stop wiggle mode. No icon on screen.
Infiniboard
Cost: $1.99
Brief Description: Lets you vertically scroll your home screen pages. Using Infiniboard you can add as many icons as you want on each page, and access them through a flick up and down. It’s really cool, the options are accessible under your general setting on the iPhone, no icon.
CyDelete
Cost: None
Brief Description: Allows you to remove Cydia packages like any App Store applications- hold down the icon, wait for them to start wiggling, and tap the X. Without this it is a much longer process: recommended!!
Security and Privacy:
mAdvLock
Cost: $14.99
Brief Description: Locks applications, both system and not, and all kinds of other files in your iPhone with password.
Poof
Cost: None
Brief Description: Allows you to hide and unhide your applications. It allows you to hide all AppStore, Cydia and system integrated Apps.
Privacy
Cost: None
Brief Description: A settings panel that lets you opt-out of sending anonymous usage statistics to App providers/developers.
Quicklock
Cost: None
Brief Description: Puts an icon on your springboard, that when tapped, locks the device. Same as pressing the top, lock, button. This will not replace the top lock button if yours is broken.
For gaming:
GPSphone
Cost: $4.99
Brief Description: An emulator for Game Boy Advance games.
N64iPhone
Cost: $2.50 and also free ‘lite’ version
Brief Description: Nintendo64 emulator for iPhone 3GS and iPod touch
Snes4iPhone
Cost: $5.99
Brief Description: a Super Nintendo emulator for the iPhone and iPod Touch. Do you sense a theme here? people want Nintendo games on the iPhone.
TapMania
Cost: None
Brief Description: A Dance Dance Revolution and In the Groove simulator.
Navigation:
xGPS
Cost: None
Brief Description: Voice guided iPhone GPS
Backup Apps:
AppBackup & AptBackup
Cost: None
Brief Description: AppBackup lets you back up and restore Apps that you have purchased from the iTunes App Store. AptBackup does the same for Cydia Apps.
Other apps
iFile
Cost: $4.00
Brief Description: A replacement for Finder or Windows Explorer on your iPhone. You can copy and move files, set permissions, and transfer files through its web server.
MxTube
Cost: None
Brief Description: An iPhone YouTube videos downloader, lets you search and download two videos at a time, the rest will be in waiting status. You can watch all the downloaded videos on the videos tab.
SwirlyMMS v2
Cost: $12
Brief Description: A native MMS application for the iPhone with built in voice recorder, and ringtone creation capabilities.
Connectivity/Network
PdaNet
Cost: free trial, $29 full
Brief Description: Internet tethering, create a Wi-Fi hotspot using your iPhone’s 3G service.
Netatalk
Cost: None
Brief Description: Lets you drag & drop files onto the iPhone, it will show up on Finder as a shared device. It will also work for the iPad!
OpenSSH
Cost: None
Brief Description: A background system that allows you to connect to your iPhone over Wi-Fi and transfer files from your computer to your iPhone. Note: No icon will appear for this app.
Mobile terminal
Cost: None
Brief Description: A terminal emulator application for the iPhone. It is NOT an SSH client, it can however be used to execute a console ssh-client application.
Spirit Jailbreak is Available for iDevices
Accessories & Apps: Beta Testers Wanted
iOS Firmware/IPSW Download Guide
Legacy iTunes Download Archive
App Store Top Charts
iPhone and Android Resale Value Charts
USA iPhone Carrier Plans Compared
Complete iPhone Jailbreaking Guide 
Complete iPhone Specification Matrix 
I tell you one reason to NOT JB your iPad…touch accuracy suffers.
There’s a bug in the JB that makes your taps offset. It’s really annoying.