Used them In Canda, all the company phones were set up for it and was actually pretty damn handy. SMS isnt popular over therte so it was a quick way of finding out in a 15 storey building where your staff have all gone :)
I dont think they saw them in the same light :)
I think a lot of UK phones support it but the operators dont. certainly my N80 does and I remeber bunnies N60 deing able to do it to.
Phones were Motorola V60s I think