So I followed the same instructions from LMT, but kept all of the .inc files within my main weblog and simply put the calls for the include file in my sidebar.
I created a new category "Other Blogs" and a corresponding otherblogs.inc file. To keep the posts in the linkblog from appearing in the main index, master archive and monthly archive pages, I modified the MTEntries tag to only include certain categories (all but the "Other Blogs" category essentially as follows:
CODE
<MTEntries category="Announcements OR News OR People OR General" lastn="15">
The tag in the otherblog.inc file looks like this (also modified to alphabetize the list of blogs and show only the 5 most recent Blogs entered):
CODE
<MTEntries sort_by="title" sort_order="ascend" category="Other Weblogs" lastn="5">
(I think you could use a plugin to do the same thing more elegantly, but this works if you have a small number of categories.)
The .inc file in the tutorial turns the title of the post into a link, creates a permalink to the entry and uses the excerpt field for a description or comment. This leaves the "more entry" field available for other things like a review of the link or blog, a screenshot, or any other information you may want to include about the site you're linking to.
I think there's some advantages to using this method: there is no need to rebuild after adding a new entry to your sideblog; there is no need to figure out how to search multiple blogs; and there's no need to have a separate feed for a sideblog; you can display only a few of the entries in your sidebar and the whole sideblog can be viewed as it's own page in the Category:Other Blogs page.
Click here if you want to see what it looks like on my site.
There might be a really good reason to use a completely separate blog, if anyone knows one I'd like to know as I just finished this and would hate to get attached to it if in the end it turned out to have a big disadvantage.
I thought I'd throw this up here for others looking for an easy solution.