Being that there are those that watch every little thing I do with my blog (which isn't a bad thing by the way), I placed a Bing search on the right sidebar.
For the longest time the major search engines have had the ability to embed their service on your site. You can configure them as such so they only search your site/blog/whatever. But the problem has always been that whenever anybody performs a search using one of these, it takes you away from your site - and that's bad. Bing is the first of its kind that allows search results to be shown while not doing that. Perform a search in the sidebar and watch what happens. A box will appear without forcing you to go anywhere else - and that's just plain awesome.
Bing has indexed enough of my content to where I believe anybody who uses it will find what they were looking for here.
The internal WordPress search sucks and always has. It doesn't do operators or sort results properly. You can't use quotation marks (that really screws it up) and it's just bad all around. For each successive release of WordPress, the search has never improved and probably never will.
Google and Bing on the other hand have all the great stuff you come to expect from search. Bing wins because it doesn't force you outside the site just to use it. That's cool.