Need to update my IPhone 3G?

Need to update iOS 5 or later. I currently don't have computer access, so how can I do this. Does anyone have any ideas.

I'm 99.9% sure you can't update without a computer.

On my iPhone to update it via the phone itself:
- Go to Settings
- Go to General
- Click on Software Update
- Follow the instructions this should allow you to update your software directly on the device

Well, the second answer is exacely good and right.