If you have subscribed to Voicemail to Text transcription, you can post text to your Facebook wall just by speaking into your phone.
Follow these steps to post from voicemail:
1. From your voicemail Inbox, tap the Compose menu option . You will now be prompted to select the type of message to compose.
2. Select Transcribe to Facebook. An on-screen prompt to "Speak now" appears.
Note: This option will appear only if you have subscribed to Voicemail-to-Text transcription. It will not be available otherwise.
3. Speak the text that you wish to post on your Facebook wall. When you have finished speaking, the Visual Voicemail application will display a transcription.
4. If you want to edit the transcription before sending, tap the transcribed text. (The on-screen keyboard will appear.)
5. When you are satisfied with the text, tap Send to post it.