Whited00r, recently developed a custom iOS 5 version that can be installed on the older iPhone 3G/2G and iPod Touch 1G/2G That doesn't support iOS 5.
iPhone 2G:
Download iPhone 2G Normal 5.1
Download iPhone 2G Unlocker 5.1
iPhone 3G:
Download iPhone 3G Normal 5.1
Download iPhone 3G Unlocker 5.1
iPod Touch 1G:
Download iPod Touch 1G WD5.1
iPod Touch 2G:
Download iPod Touch 2G WD5.1
Click on iDevice
Now, with Whited00r 5.1 Get your old devices back to life, you don't even have to jailbreak your device, it's just a Custom Firmware Could be done by using iTunes.
Moreover, it brings to you most of the iOS Features including multitasking, reminders, video recording, service like iCloud, although you wont have the iOS Notification and i don't think it will be running smoothly on these devices. But there are a lot of happy reviews from happy customers so i think that won't happen so give it a try.iPhone 2G:
Download iPhone 2G Normal 5.1
Download iPhone 2G Unlocker 5.1
iPhone 3G:
Download iPhone 3G Normal 5.1
Download iPhone 3G Unlocker 5.1
iPod Touch 1G:
Download iPod Touch 1G WD5.1
iPod Touch 2G:
Download iPod Touch 2G WD5.1
Click on iDevice
iPhone 2G | iPhone 3G | iPod Touch 1G | iPod Touch 2G |