You can delete native apps only if your device is jailbroken, using a program such iPhone explorer.
You basically drag the relevant folder out on to your desktop. But please be warned some of these native apps are connected to other functions on your IDevice. The last time I used such a programme was to unjailbrake a 3GS, I deleted the cydia folder and rebooted one unjailbroken phone. Personally now I would just do as advised here and stuff any unwanted apps in a folder
When you update/restore your IDevice they will reappear anyway.