http://googlevoiceblog.blogspot.com/2010/03/google-voice-turns-1.html

We wanted to thank you for letting us know what you think, and we hope you like the improvements we’ve made since then.

Many users have voiced their complaint about certain missing call screening features. In particular, I’m referring to the following:

1. Once a call screening name has been recorded, there is no way to delete it or force it to be re-recorded. So if you friend calls you and hears the prompt to record his name and he says “What the F***?” as his name, that is what you will hear every time that person calls you. This is especially not good if you have little ones that might answer the phone.
2. The proposed solution to that problem is not a solution at all. Add that person to your contacts and their name will be “read” instead. This is much more of a hack than a fix, and from what I’ve read it doesn’t even always work.
3. Suppose the person is calling via a business that has a phone system that gives every outbound call the same caller id? For example, say my boss calls me from work and records his name. Now any time anyone calls me from that company, I will hear my bosses name even though it could be any number of people calling me.

It seems like a terrible oversight that users can not manage the recordings. Also, it should be configurable to force a recording every time for certain numbers (which would solve the 3rd problem listed above).

In my opinion, Google Voice still has a long way to go, and it’s disappointing that it has been live for a year with not even a word of fixing these issues.