Different notification sounds for sms and email?

I use SMS Popup to manage notifications for text messages, and leave the email notifications to be handled by the default notification settings. This allows me to set custom sounds, vibrations and LED flashes (hardware allowing) for SMS text messages that separate them from emails and other notifications.

It's important to understand the differences between a platform like Android and the traditional "dumb phone" platform.

With Android, very few applications are "special". By special I mean the OS is aware of them and treats them differently. In Android, an application actually has to manage notifications themselves, there's no way for the OS to somehow figure it out and expose a setting for it. Notification sound customization has to be exposed by the individual application developer, not through Android itself. When an application creates a status bar notification, by default Android will play the sound that you set in the default Notification setting. But the application can explicitly provide a different sound to play. The application would have to manage that themselves (it would be nice if Android allowed apps to register for custom notifications and then it could provide a central location for all of them, but I'm not aware of a facility for doing this).

If a particular application doesn't provide support, contact them and ask them to add it. Take away a star or two from your rating in the marketplace and explain why you did so. Many developers actually listen.

Compare that to the traditional "dumb phone" platform where everything is tightly coupled and controlled. The OS can easily expose settings for individual "apps" because they're baked in and don't really change.

But, sadly, Skype does not allow one to customize their notification sound.

Does anyone know how to customize the notification vibration ?

You can customize the Notification settings for both Gmail and Messaging in each of the apps separately.

In Gmail press menu and go to More->Settings and look at the Notification settings section.

In Messaging press menu then Settings and look at the Notification settings section.