Installer.app will still be useful in the next device.
Putting Installer.app (AppTapp) on your jailbroken 1.1.1 iPhone
GUI for Installer.app now available: Third-party iPhone apps without the Terminal
Installer.app 3.0 beta released -- better access to third-party iPhone apps
Creator of iPhone Installer.app on Apple's native app stance, the future of Web apps and more
A Mac OS X-style Dock for the iPhone debuts
Complete guide to iPhone jailbreaking and applications
Restoring with iTunes 7.4 then re-attempting jailbreak can be very, very bad.
Problems with 1.1.3 jailbreak: try the new version and other fixes
Delete iPhone SMS messages one at a time