Rotem925 created a very cool app, iBuilder.
It let’s you create your own Firmware with all you can desire already installed

the official words from the developer are:

-Its a bundle builder, it will build a bundle directly from the installer,
package it so that the installer will recognize it
-It supports installer sources too

Known BUGS
There is a problem with the directory /private/var
looks like it cant load the carrier plist.

–end developer comments.

the app is still in beta, but this looks like it’s going to be a very very very nice app.

No more installing every single app after a restore, just create the image with all the apps you need, and tata, your iPhone is instantly installed !

You can download the app from here

 via http://iphonefreakz.com/2008/04/20/create-your-own-firmware-with-ibuilder/