It's been a while since I gave some insight to tuning your voice mail with regular phone using GSM MMI codes. Very useful for people annoyed by voice mail, yet unable to afford losing it just yet.
One of the biggest updates is that GrandCentral is now called Google Voice. Although still closed for general registration, you can sign up for an invite, which you will get in about one or two weeks. I tried.
Another cool thing I learnt was that Android interface allows you to setup alternative voice mail without having to hack with MMI codes (Menu > Settings >Call Settings). See screenshot below:
Among other new things you can do with Google Voice is be ability to easily look for a number that translate into some phrase (Settings > Phones > Your Google Voice Number > Change), also called phone vanity phrase. Check screenshot below:
Just type your word and it'll search for available numbers for you, very cool. Existing Google Voice account holders will have to pay one time $10 fee to change the number. But I think it's worth it.
Worth mentioning that Google Voice now transcribes your voice mails. Supremely useful feature. You can glance at it and see if a voice mail is worthless and pointless, you can just delete it without having to listen to it. On the other side, people who have accent shouldn't expect their voice mail to be transcribed correctly at all. Or if you someone has a name that isn't common, most likely, that name won't be resolved correctly. For instance, my name — Vlad — usually resolves to Bob, Blob, or Void. 
Lastly, there's a fantastic native Google Voice App for Android that makes things very transparent. There is one that was released for iPhone, but was pulled from iTunes App Store shortly; but that is an issue to cover some other time.
And finally, some people told me that they'd never use Google Voice or Google Mail, or anything google for that matter for privacy reasons. Well to those I have one thing to say — You are mistaken if you think you will find privacy in Verizon Wireless or Comcast when it comes to your phone or email address. Privacy is like Santa Claus, people just _conveniently_ pretend that it exists when needed. Got something to hide? Barricade in your house and don't use anything. On a serious note however, if you're that paranoid, 
check youmail service as a parcial alternative to Google Voice.