Carol Phillips 

Online panels are superior to telephone surveys. Those who are still doing surveys the old fashioned way are paying a high price, and not just in dollar terms. Telephone surveys have always been suspect from a representation perspective. Who really believed that they ever represented a 'random sample? Now with many respondents believing that do not call applies to polls as well as sales calls, 8% of the population completely disconnected from a landline, do not call lists now extending to cell phones, anyone who uses the phone for survey recruiting should beware.

That's not to say online panels are without their problems as well. I can speak from first hand experience that online panels are not all of equal quality. In general, I advise clients to stick withpanels that use email over Internet, have enough representation of young men and minorities to be useful and balance their samples mathematically to census figures. Beyond that some good indications of quality are response rates. Panels that are 'grabbing whoever they can and pelting them with questionnaires probably are going to have lower response rates. Another indicator is how respondents are compensated. You don't want professional respondents.

Finally ask whether the panel allow you to recruit qualitative research respondents from among survey respondents? This powerful technique is quickly becoming popular as a way to get extra insights about difficult to recruit for populations such as concept acceptors or super heavy users.
I am aware of just one panel that meets all of these criteria, BIGresearch. Unfortunately, their panel is not available for custom research unless you are already a subscriber to one of their syndicated panel products. If you decide to go with a self-serve panel such as those offered by Survey Savvy, Zoomerang, Harris or Greenfield, just be sure you know what you are getting. And (hint) be sure to check the back-end analytic software.

Carol