TD: anyone here had SMS's arrving up to 12 hours after sent from a phone to another ?
Yes.
Also I use a local VOIP service, like Skype, which allows me to type a SMS on the computer keyboard, instead of farting about with all those silly little mobile phone keys, where 1 key is used for 3 or 4 characters, then I just 'send' to a mobile phone number, but it isn't instantaneous and replies are sent to the computer, not back to a mobile phone, so it isn't very convenient if you want a reply.