Wordpress Plugins I Use Atm
-> Displays adsense ads
-> keeps spam out of my comments
-> Embeds MP3 files with a nice flash player interface
-> helps to embed videos from various sites (youtube, google video, …)
-> Adds the ability to create votes in my posts
-> creates sitemaps for better indexation thourgh google
-> notifies me though jabber when a new comment is added to one of my posts
-> I once embedded a quicktime video into my blog. These are the remains (nice for e.g. movie trailers.)
-> lots of statistics in your blog admin interface
-> makes adding tags more easy
-> adds the nifty digg, stumbleupon, mrwong … buttons at the end of posts
-> allows users who commented to something to receive an email when someone else commented on that post
-> transforms stuff like "1 slash 2"; into 1/2
-> "1 click"; wordpress update
-> whenever you're too lazy to use phpmyadmin
-> hmm… don't really remember when I used that one :) But apparently "This plugin eases insertion of Jeroen Wijerings FLV Video Player";
-> the little stars you can use to rate posts
-> "The wpSEO plugin rewrites your blog title, META-description, META-keywords and META-robots so these are more user and search engine friendly.";
-> That's what I use to embed my GPS traces (.gpx/.kml files)