I'm really loving using my new Google Voice service.
Here are the best things about it:
> it's totally free
> when Google adds new features, I automatically get them
> it turns voicemails into transcripts that get texted to me (perfect for when I'm in a meeting)
> it allows me the capability to download my voicemails as an mp3 file (now I can save precious messages)
> it allows me to record phone conversations (of course not without the other party knowing)
> it allows me to hold conference calls with basically an unlimited amount of participants

Here's a great example of it's voicemail feature.