Thanks for your comment, I don’t get too many comments from people that I do not know and its nice to know other people are reading my site. Lots of traffic, lots of subscribers, but no comments, I just can’t figure it out.

Anther thing I should point out is that I am still learning the whole SEO thing. I have just started making money of my sites and I am reading constantly but search engines update the way they work on a regular bases. (just covering my ass)

The sub directory.
I am told by numerous sites (that I can’t find) that some search engines (google, yahoo) also put weight on how deep the directory tree is.
For example; http://www.abluestar.com/blog/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v.htm
would be weighted less then
http://www.abluestar.com/blog/abcdefghijklmnopqrstuv.htm

This is a speculation because no one really knows how the google algorithm works out side of google it’s self but it makes sense that you would keep your good content near the top.

This isn’t that big of a problem, and if you have everything already set up I wouldn’t change it. But given the choice again I would install my main blog in the base directory.

Next point.
For a family site, or a dev site it makes prefect sense to have a sub domain, you don’t want causal readers. On all your other content you want people to find (bleed) your other content and having it all under one roof helps… I’m not sure exactly how it does work but that stats show that it does.

The reason that your blog and your wiki don’t rank the same for the same content is because of google’s supplemental results thingy. You get a small penalty for pages with duplicate content; google uses the page that is linked too most as the primary and all others as supplemental results. You could then steal other peoples content and make sure that it is linked more then the creator site, google would see more incoming links to your page and rank it higher then the creators site.

I hope I helped you even a little,
If you have any other questions, even on subjects I have not talked about, feel free to contact me.

There are many reasons why one would use a sub-folder. For example, you are using a CMS for the root of your web-site, and instead of using the not-so-nice blog feature of your CMS, you install a specialised blog engine (in a sub-directory) and you integrate the theme within your CMS.
I do not see why such an installation would be bad for search engine? If it is the case, then the search engine should be updated, not the structure of your site

For the second bullet, about the sub-domain. It depends of what you want to do. If you are hosting two blogs on your site, e.g. one general for everyone about researches, studies, etc. you are doing, and a second one to keep in touch with relatives and acquaintance ; I think that using a sub-domain for each is then good. Because, they are unrelated.
In addition, I am not quite sure that this is true. I have a really cheap hosting and I cannot have sub-domains (apart from the www). So, I’m using 2 sub-directories one for my blog, the other one for my wiki. Some articles in both the blog and wiki are on the same topic. But it seems that articles from the blog are higher ranking than the former of the wiki in search engine results. So not using a sub-domain does not seem to mean that went a project gets higher ranked, the other can benefit from that…