SMS Gateways provide an easy of sending SMS messages to mobile phones and pagers. The short message limit (160 septets) can be avoided by sending messages as a sequence of short messages.
There are several companies promising to deliver your SMS. You just need to decide what suits you best... a web based product, PC software or bulk sms solution that plugs in to your database.
Some Bulk sms gateway solutions include sending SMS via a web based interface or connecting your own API application direct to their gateway vi the internet. Depending on your requirement, you could select a sms solution for your company.