For US wireless subscribers, you can set up a free account with Callwave and transfer your voicemail messages to Callwave. You set your greeting message, and when someone leaves you a message, the voice message is converted by Callwave to a text message that is forwarded to your phone.
You don't need to check your voicemail to check your messages, just read the text message with the written version of the voicemail. The voice message is also forwarded to your email account where you can listen to it.
www.callwave.com