Several good comments already to the first note on this line, at Communicating Science I'd like to continue a fair amount of discussion there.
Here, I'm pulling out some of the specific suggestions folks have made for more focused discussion and elaboration. All, I'll note, are from the commentators rather than myself.
Eric asked the important question of whether I mean ideas for me, personally, or for scientists in general. I mean both. It might be a good idea for scientists to appear regularly on The Daily Show and Colbert Report. But that's probably not a good venue for me (but if John Stewart or Stephen Colbert give me a call, I'll give it a try and find out :-). Worse would be some of the anti-scientific yelling shows on TV or radio. On the other hand, I only learned about Science Cafes by accident and that's a very good venue for me. (Both that I enjoyed it, and that my host and audience did.) There probably are a lot of others.
If I read jg and eric right, in addition to blogs, educationally-oriented web sites are also something to do and have. I did work on one in the 1990s -- http://www.radix.net/~bobg/ -- but had stopped that and thought that these days blogs might be the preferred route. Certainly google gives higher scores to blogs than web sites (my blog note on sea level change shows up much higher than my sea level FAQ that's been out there, and multiply linked to, for over a decade). But what sort of organization should it have? Encyclopedia was mentioned, but I don't see much improvement from encyclopedia over blog. Neither is very organized or coherent. But maybe I'm not seeing the virtue there. Comments welcome on that, and on alternate structures you might like instead.
jg and bart mention trade/industry journals and groups. I'm not sure either what groups are meant, nor how to publish there or speak to them. The scientific societies (AMS and AGU, for instance) have in-house magazines for their members -- Bulletin of the American Meteorological Society, EOS: Transactions of the American Geophysical Union. But the audience there is already pretty knowledgeable about climate, and does routinely have articles on the topic. Plus, with about 60,000 members between them (and a lot of overlap), that seems an awfully small target.
Any suggestions on outlets to write for, groups to speak to?
And, of course, new and different thoughts are still welcome.