An essential point raised in another StackExchange beta I participated in was that at launch a community pretty much sets the "level" of voting that occurs. For example, on some sites a good question or answer might frequently get 30+ votes, while on another site 20 might be considered outstanding. Once people have a certain level in their minds as representing a good or excellent question, they're much less likely to vote when the score already reflects their existing opinion of a question or answer's quality.
During the beta we have the chance as a community to, as Jeff Atwood recommends on the Stack Exchange blog, vote early and vote often. In so doing, we increase the effectiveness with which we distinguish between different questions, and also help to encourage participation because people who contribute something useful feel rewarded for doing so. Setting a "high" level of voting where good, great, and outstanding questions and answers receive a large number of points will produce great advantages for the community in the future.
With this in mind, I've decided to browse back through the full list of questions sorted by votes, and vote up all those questions and answers that are good, great, and outstanding; and I'd advise others to do the same. By creating a culture of frequent voting now, it will be far less of a chore to encourage the community to be active in voting later!