Here’s a neat trick I found today. These codes only work for Verizon Wireless, but there are similar codes for other carriers…
You can set your cell phone to forward to ANOTHER PHONE NUMBER instead of voicemail. It’s easy to do, and easy to turn on or off. This is really useful if, for example, you’re going overseas and won’t have your cell phone turned on. Just forward your cell phone to a VoIP line (e.g. Vonage, Broadvoice, GizmoProject) and then you can check your messages over the web. Note that your cell phone will still ring if it is on (this works exactly the same as voicemail forwarding).
Here’s how to make the magic happen:
To turn forwarding on, dial *711xxxyyyzzzz (where xxxyyyzzzz is the phone number)
To turn forwarding off and return to voicemail working like normal, dial *73