There is an app to send/read SMS from the desktop using the Internet? Possible Duplicate:
  How do I send SMS from PC through Android Phone or to Android Phone?  




There are many apps to send/read SMS from the desktop using a Wi-Fi connection, but my cyanogenmod rom doesn't play nice with my Thomson router so I can't use them.

There is an app that uses the 3G internet connection for that?

Better if it's a webapp.
I have used DeskSMS over a Wi-Fi tether, and it works fine.

It is supposed to work over 3G, but I have not tested this.