ok i have an ipod touch 2g and it has been jailbroken for 8 months now,the benefits are endless,for example you can
-customize it by adding themes like a windows theme or millions of other themes,you can change your lock screen to have the weather or your facebook,twitter messages or whatever you want,you can change the slider to anything or have just a button to tap to unlock it,you can have five icons down in your dock instead of 4.
-you can install 3rd party apps from cydia that are not on the appstore,some of these are really awesome.
-you can install almost any app from the appstore for free once youve jailbroken through ann app called installous or from any website you can download the ipa file and drag it into itunes if you install appsync 3.0
-from cydia one of my fav apps there is yourtube witch adds a little button on the top right of videos when you watch in your youtube app that lets you download the video straight to your device.
-also you can put your apps into folders like your games in a games folder and so on..
-there is also an app called dtunes that lets you download any mp3 for free.
-then there is iprotect that lets you lock each app indavidualy,for example you can lock your email app and when you tap it it will ask for a password,this app also serves as protection if you have an iphone and it is stolen if the chnge the simcard a text will be sent to a pre determined number with the new phone number.
-there is udid faker wich alows you to trick apps if you have been banned for cheating or anything.
-there is rename witch allows you to rename any app you have to anything you want.
-there is backgrounder witch lets you run ann app in the background while you go to another app then come back.
-then one of the best is open ssh witch gives you acces to the root files so you can wirelesly add apps or anything you want without using itunes
-sb settings give you complete controll by swiping the top status bar and a complete menu will come that lets you turn off or on wifi,bluetooth,ssh,location ect.... you can controll brightness or take down a note anytime in any app.
-you can also hide icons if you have something you dont want people to see you can hide the app.
so this is about 3 percent of what you can do if you jailbreak.
I bought the iphone 3gs 2 months ago and i jailbroke the second i opened the box,i couldnt have it any other way,
on my iphone i have pictures of my fav people right on the lockscreen,i just tap them and slide and it will call them
my most used is snappy,i hold the status bar for 1 second and the camera pops up even if im in any app,this thing can take mulitple pics per second.
i can create ringtones directly on my iphone.
i can create a blacklist to bloack any number from calling me.
so all in all this is definatly worrth doing and if you have a problem just restore in itunes,I bought a iphone from rogers last year and jailbroke it but i decided to return it cause i realized how much surfing the net i do and it would of cost me a fortune,i just restored it in itunes and returned it to the store,they can not tell the difference once it is restored it is back to the way it was when you bought it.now i bought the new iphone 3gs with bell and im happ with it
-oh i also blocked the phone from using the internet data completly exept wifi so i dont risk using aslot of data,for me its perfect cause i have access to wifi almost everywhere i go and if i want to use 3g or edge data i just flick a button in settings.