If you go here: http://twitter. com/devices It says it's free, but "standard message and data rates may apply." I do have unlimited texting, but do you know if "data rates" have to do with internet? I can't afford to have any extra costs on my phone. :) Thanks.
Answer on Does using twitter with text messaging cost money if you don't have mobile web access?
No, I doubt so. By text messaging you're not incurring data charges; I presume they will convert your message through their servers.
However, if you use their application it will be through the internet so "data charges" will apply. I think that's what they're referring to.
Certain text-to-tweet capabilities include a link for you though, so make sure to not click those unless you have WIFI.