Well now you can - easily and cheaply with CleverVoice!

Powerful & personal: better than text or email - say what you want to say, in your own voice - without disturbing people with a call. Stand out by delivering a personal message.
Save time and money: cheaper than making calls to many people - send a message one-to-one, to a small group or to hundreds of people - just at the touch of a button.
Interactive: you know who has listened to your messages – and can track their responses.
Quick & Simple: easy to use - no software to download for you, or the recipients of the messages.
Works anywhere & everywhere: you can send messages to any mobile phone, anywhere in the world.
Convenient: recipients get an alert message which can say who message is from and the subject (rather than "you've got voicemail") - so can choose to listen immediately, or wait until convenient.