The WordPress plugin architecture is really cool.
I just installed two plugins in my sidebar. The first is Tom Gilbert's del.icio.us plugin. This displays the last 10 links I saved in del.icio.us a link aggregator. Del.icio.us makes it really easy to save your bookmarks and access them anywhere.
The second is Ted Parson's WP-Scrobbler plugin. This displays the last 10 songs I have played and submitted to AudioScrobbler on my blog. Very useful. I was to lazy to try and use my code I have written for the front page of my website. Maybe one day I will. Right now Ted's version works just fine.