This is usually not a topic being written about on this blog, but it is important enough to be mentioned:
During the release of wordpress 2.1.1. some part(s) of the wordpress infrastructure got infiltrated by a cracker. The cracker then included malicious code into the wordpress codebase.
What this means is this: If you run Wordpress 2.1.1 you must upgrade to Wordpress 2.1.2, otherwise your hosting-account might be in jeopardy!!!
Read more about the unfortunate event at Wordpress.org.
(Needless to say, this blog is already updated)