T. Ryan Gregory asked that question yesterday, as he launched his third blog at Nature Network. In the post, he mentioned his second blog, DNA & Diversity at Scientific Blogging. So I went over there to have a look - and realised that I had just registered at that site the previous day. At the time, I knew nothing about the site, but now I poked around some more, and it seems reasonable and credible. So I now have a sixth blog, Tropical Ecology Notes (ok, in reality it's my fifth, since I can't really count a blog I don't update).
Scientific Blogging seeks to be science-only. At the very least I can cross-post my tropical biology posts over there. It might be nice to put together a collection like that. Since everything gets a short while on the front page, let's see if anyone reads it. If so, great. If not, well, I'm not creating content specifically for that site, at least not yet, so the marginal cost of adding a post there is very small (unlike here, where I am blogging for almost no readers). We'll see - it could be fun. And it could fill a useful niche - there don't seem to be too many people blogging about tropical plant ecology.
Update: Gregory mentioned that Scientific Blogging was a way to reach a wider audience than he currently has at Genomicron (which is probably many times the readership that I have on my WordPress blog). Based on the one article I have posted there, I think he's right.