How High Can Iphone 3G update?

Wondering if anyone knew how high the iPhone 3G could update to? And if it can't update to IOS 7 what can it NOT do?

IOS 4 is the highest it can go.

That means you have no iCloud, no iMessage, no FaceTime, and won't be able to run hardly any apps.

You can still make calls, run music, and browse the web… But some features won't work and security will be an issue.

4.2.1 is the last firmware it can ever get.

You can update to iOS 4.2.1.It's pretty old, so most new apps will not work with it, but there are plenty of games and apps which ARE compatible. You can find them in iTunes store with this tool:
https://sites.google.com/site/iossearch/

The highest iOS you can go is 4.2.1

This site has a custom Google search that lets you find all the apps on the iTunes store that are still compatible with iPhone 3G and first generation iPad and iPod touch.

Just do a search and you will see the option for the different iOS from 2.0 to 4.2.1

http://www.oldiosapps.com

Hope this helps