Emoticon charges
Hi there Kjw88.
When an SMS becomes an MMS depends heavily on the handset settings. Emoticons can trigger the change, as can using more than 160 characters. You may have to consult your handset manufacturer, or search online, for further clarification.
Most handsets will allow you to enable and disable MMS messaging completely, if you're worried about excess charges.
If you have any other concerns please don't hesitate to drop me a PM 