It has een said that you should always be careful on what you write of blog on the net as more and more employers check you using google to see what you're up to in the virtual world. I think that's something to keep in mind. Personally, I blog a lot but mainly about business, Web 2.0 (here, of course) and not so much about other subjects besides hobbies and such. So I don't think any possible employer would find anything he or she could hold against me - on the contrary. In my field as a consultant, I think I could actually benefit one day from the blogs I publish, as people will be able to see I am serious about it and I have actual knowlegde in the field.
So should you assume a virtual identity on the net whenever you want to blog, publish or discuss topics that could harm your career one day ? Not me. I am 100% behind every word I publish. But for some people in other fields, maybe they should. What do you think ?