There are certain applications on your site that you can and really should pass on to a third party to manage. By doing this you prevent unnecessary calls on your server making the use of bandwidth that your site is taking a whole lot smaller and therefore faster as the server doesn’t get overloaded. It is something doesn’t think about until your server demands that you pay more as you are causing heavy loads. If your site becomes very popular these bandwidths increase exponentially. While that is fine in some ways in others its not. If your bandwidth is causing blockages it means that it will also be far slower loading. So consider off loading some items that are actually both taking up too much of your time and your bandwidth.
For example are you doing your own RSS feed? Rather hand it over to one of the services that specialize in this like Feedburner. This is a Google owned product which has recently been taken over by them and is a good way of saving your site from constant call by places like technorati where they are constantly looking for update. Google will know when you have updated your blog because there is an automated ping from WordPress so they will check and update. It all then works together as the feed doesn’t come off your site except for the Google draw. This is then sent to you Rss list via Googles servers.
It is the better of the feeds and the one I would say would probably be best suited to your blog as it is well integrated with WordPress.
Rather than use your own site search plug-in or panel ship it out to one of the search engines Google has provided you with the means to use their code to do a blog search with the insertion of an API key. You will need to join Google to obtain this but that is simple and if you already have a Google account you can use that to log in.
Yahoo has a similar search facility called Boss which works in much the same way. The difference is it doesn’t display ads and it is far better integrated into your blog. This is the one I personally would go for.
If you are using a lot of jQuery tools for things like slideshows and other Ajax features it would be advisable to make use of the Google Ajax Libraries API. Slideshows and other items that are run by the jQuery and other similar tools draw a lot off your site. Google uses a network to distribute content and as a result the closest place to the person requesting the data will spring into use. This not only saves the load on your server but it will be a whole lot fast for the user.