Hello,

This is very minor and secondary proposition.

We just created an smsemail.module http://drupal.org/project/smsemail and I would like to propose you to put your one into SMS package, so my one will not be alone there:) I mean set package=SMS in your info file.
Now, you don't use package so smsgateway.module is put into Other section. We can start a new section called SMS where all future SMS related modules may be included.

Thanks.