While not new, spreading the risk through pools also encourages more angels to stay in the hunt for the next big thing in parlous times like these. Many, of course, are doing so more cautiously than before. Average total deal size in 2007 dropped to $450,000 from $500,000 in 2006, according to the Center for Venture Research.

They're also most likely to invest in what they consider to be "surefire" areas, including green technology, and Web 2.0 applications like social networking sites.

In addition, safer, established businesses are attracting more interest, especially those run by founders with previous entrepreneurial success.

Dave Nelsen, C.E.O. of TalkShoe, a three-year-old business that allows social network users to talk online, raised more than $400,000 in March from two angel groups. His background in starting, running, and selling CoManage, a telecommunications business, helped to open doors. "I had a track record for building a company and raising money, and that's what really helped us," he says.

When angels do look at start-ups, they are raising their standards. Former Google executive David Scacco, for example, invested in 10 firms and said he expects to do about the same in 2008—with a difference. "I'm holding them to a higher bar," he says.

That means considering only businesses with at least a working prototype or, in the case of Web enterprises, those that can show increases in the number of users.

Recently, for example, Scacco said he turned down a suitor with what he considered to be an interesting social networking application, because it wasn't up and running; as recently as last year, Scacco added, he wouldn't have been deterred by the fact the service hadn't launched yet.

Scacco said he also spends more time questioning companies, meeting three or four times with managers over a period of three or four weeks, compared with the two or so get-togethers he held before. And he conducts more of his own market research.

It also helps if a business already has a prominent backer. Early this year, Gregg Smith, C.E.O. of Acuity Mobile, a two-year-old company that provides marketing messages on cell phones, closed on a major round of funding.

While he can't reveal the total amount, 25 percent of it came from two angel groups and the rest from Navteq, a Chicago-based digital mapmaker. One angel group made its offer contingent on Navteq's public commitment. The other waited until after the deal was actually signed.

Ultimately, as financing for new ventures from private equity plummets, angels expect to be in an increasingly stronger bargaining position. Angels report asking for such favorable terms as additional equity if certain goals aren't met or more warrants to buy shares at a specified price.

It's not surprising, then, that a majority of angels anticipate that the quantity and quality of deals will increase this year, according to the Angel Capital Association. Says Greg Baszucki, an angel in Portola Valley, California, "If the market goes down, it will be great—a great opportunity."

That is, of course, as long as they choose the right companies.