On overture I can find out what the bids are for a given keyphrase. How can I do the same for Adwords?
The reason you can do this on Overture, (and why it is important) is that your bid is the only thing that determines your position there.
On AdWords, your position is equally determined by your Maximum CPC and your Clickthrough Rate (CTR). CTR is important because it is a measure of the relevance of your ad to our users, for the given search.
(CTR = Clicks divided by Impressions, expressed as a percentage. So if your ad appears 100 times and is clicked on once, CTR is 1%.)
Because CTR is 50% of the equation that determines postion, knowing what your competitor is paying is not particularly useful information.
In fact, it is entirely possible for you to appear above a competitor who is paying more that you are - if your CTR is much better.
Hint: Take a look at the Average CPC column of your account stats to see what amounts to 'the going rate'.
AWA
Because CTR is 50% of the equation that determines postion, knowing what your competitor is paying is not particularly useful information.
I have to disagree. From a business standpoint, knowing what you competitor is willing to pay can tell you a lot about a competitor. And knowing their bid price and position, you can get a rough estimate of their CTR and would be able to directly compare how your campaign runs against theirs.
From Gs standpoint, I can see why they don't publish these numbers, but it is very useful information.