Twitter's web UI suggests it's allowed, and I can post 140 象 in one tweet. In practice, tweets get fragmented into multiple SMS anyway, so while this might hav

Twitter's web UI suggests it's allowed, and I can post 140 象 in one tweet. In practice, tweets get fragmented into multiple SMS anyway, so while this might have been the aim, it's not the implementation they've ended up with. Also, while you may wish SMS was Unicode, that's not actually likely. The number of characters you can fit in one SMS will vary depending on whether you use more than one charset, and what your operator and device support. Most SMS in the US/UK/Aus etc will be sent as 7 bit GSM, allowing for 160 characters. 8 bit allows for 140 and UCS-2 allows for 70. (This is assuming no UDH, i.e. no fragmentation)