Upgrading Iphone 2G to iOS4

[Burner>>]

Hi Guys,
since have mi 3GS in iOS 4.0 without 3.1.3 SHSH, Im patiently waiting for a future JB/Unock for it...
in the time being I have my OLD 16GB iPhone 2G in 3.1.3, I want to know if it is possible to take it up to 4.0/4.1, I know the performance is going to suffer, But...

Is there anyone out there who has tried this??
how do you do it??
how does the phone perform???

[BenderRodriguez]

Nope your stuck but there might be a cydia addon that will allow for folders which is really all u get with 4.0.2 and PDF view

[Robcoffee]

You could check out the whited00r project - google it someone made custom firmwares pre tweaked to be more like ios 4 on earlier devices that don't support it like iPhone 2g