Blogger can be set so new posts are automatically emailed to you. Blogger also lets you post by email. So by using Gmail and Blogger together you can keep a duplicate of your blog in Gmail that you can search all you want.
- Create a "Blog" label in Gmail.
- Set up Blogger so new posts are always sent to Gmail.
- Set up a Gmail filter so that posts sent to Blogger are automatically trashed (otherwise you'll end up with two copies of each entry you post using Gmail).
- Set up another Gmail filter so that posts sent from Blogger skip the Inbox and get labeled "Blog" (to keep your blog separate from your regular mail).