You can improve the speed in which your post is picked up in search engines by "pinging."

Many blog authoring tools automatically ping one or more servers each time the blogger creates a new post (or updates an old one.) That is, the tool sends an XML-RPC signal to one or more "ping servers," which can then generate a list of blogs that have new material. - Wikipedia

In essence, a ping is a signal to search engines that something is new on your site.

You can add ping sites to blog’s list of pings (typically found in the administrative area of your blog). The leader in pinging is Ping-O-Matic, which will ping the leading services all at once. In addition, a good one to add is the growing Google Blog Search Pinging Service.