If you know that you will be dealing with a specific service provider (or
small list of providers), their website will likely tell you how to turn the
pager number into an email address. Send you page to the email address, and
their gateway will convert the email into a page. For example, on Cingular
you can send an email like this:
(e-mail address removed) (where (999)8887777 is the phone number of the
pager/cell phone) and the email will get translated by cingular into a page.
Eric