As far as I can tell, sending texts to the flashforum now works as intended. In order to use this amazing new technology, you need to:
1: Register your phone number
You need to register your phone number in your profile, so the system knows who sent the message. Your number won't be visible to anyone else. You need to include the country code, as this is how the number gets passed on to the system. Interestingly, this means that if you for example send texts from Skype, you can register your Skype name instead, and it should work. However, if you have access to Skype, you probably also have access to a browser, so it would probably be easier to post in the old fashioned way.
2: Send a text to +4798767480
And that's it.
The phone receiving these texts is just my old cell phone with a normal prepaid card (from NetCom), so sending a text to the flashforum will cost you whatever you normally pay. Nothing special.
In my experience, it takes no more than ten seconds before the message appears, so it's easy to see if it works. If it doesn't, something is probably wrong (not surprisingly), so please send me an email and tell me what you did.