Chris Bowers has the numbers on the Democratic side at MyDD:

Iowa, May 30, 1,238 likely caucus goers, MoE 2.7%. No trendlines
Edwards: 31
Clinton: 17
Obama: 17
Richardson: 10
Biden: 4
Kucinich: 2
Dodd: 1
Gravel: 0
Undecided: 10
Six poll Iowa average: Edwards 27.7%, Clinton 22.8%, Obama 19.8%, Richardson 8.3%

He notes that this polling firm uses automated phone calls.

Political Wire notes:

On the Republican side, Romney is at the front with 31% support, while Fred Thompson comes in second with 15%, followed by Newt Gingrich with 10%, John McCain with 9% and Rudy Giuliani with 8%

I don't know whether Clinton and Obama are really that far back in Iowa, but I think it's fair to say that the recent ARG poll showing Clinton 31, Edwards 26 and Obama 11 was an outlier. 

ARG's likely voter screen for Iowa must be very screwed up. Their results have been very different from most of the other polling here all year.

Meanwhile, go read John Deeth's latest post to see why it's so hard to identify likely caucus-goers. Also, it's getting harder to get random samples in polls because increasing numbers of people either refuse to respond to pollsters or have only cell phones.

I imagine that Obama does quite well among the “only have a cell phone” crowd, so polls may be understating his support.

But if I were Obama, I would fire the scheduler who put him at a west-coast fundraiser instead of in Cedar Rapids on Saturday night. That was a crazy decision. He's rolling in money and is probably going to outraise Clinton in the second quarter. He's trailing in the Iowa polls and should have taken that opportunity to make the sale with party activists.

Ordinary voters won't care a bit about who came to the Hall of Fame dinner. But every one of the 1,000 people who attended can probably influence at least a dozen friends and neighbors.