Is there any way upgrading iphone without losing the 3rd party apps?

[ofirasu]

Hey,
I searched everywhere to find an answer to this question, but it seems like no one relates to it (maybe they take it for granted or something?)
So I want to upgrade my iPhone 4 from 4.1 to 4.2.1 (when an untethered jailbreak will be available), but I don't want to lose the apps I already have and the data of each app (for e.g. my score in fruit ninja :P). is there any way backing up the data before I upgrade?

[Simon]

itunes backs up that data with every sync

[ofirasu]

itunes backs up that data with every sync

But will I be able to get this data onto my iphone after the whole update process? (restoring iphone to disable jailbreak, update and jailbreak again)

[Simon]

Instead of restoring then updating just update and all your stuff will still be there (except the jailbreak stuff of course). If you do not require unlocking make sure your hosts are not pointed to cydia. If they are or if you have ever used tiny umbrella you need to open tiny umbrella first, click advanced and deselect the box that says "set hosts to cydia on exit". Then close tiny umbrella and do the update. If you dont do this you will get an error when updating.