If you have a legit reason to send out bulk SMS messages, there are a few tools you can use. One new one is ClearSMS, which will allow you to promote a new product, send out announcements to your friends and of course collaborate with employees.
This service from ClearSMS is a Web-bases SMS system, and because you do need to sign up this means that we shouldn’t have to worry too much about spammers using to fill our handsets with useless messages. We’ll have to play with this a bit, and see what we can do about opting out, and how well it works. But anything that allows groups to stay in contact with a simple app like sounds pretty good.