This is a very simple plugin to display the contents of a text file in the sidebar. The text file displayed is only configurable by administrators since it can display any file from anywhere on the host system. It can be downloaded from here.
I'm happy for this to go into the distribution or online repository, though I'm not sure how to go about submitting it.
I created this so that I could display the output from Winamp/AMIP which is a text file containing the currently playing song. It's my first attempt at creating a plugin for Serendipity and I was surprised how easy it was (following an existing example).
If you want to see it in action it can be found in the right bar on my site and is called "Now Playing". It will contain "(Winamp is not active)" if Winamp isn't open, but that still comes from the Winamp-generated text file, it's not coded into the plugin.
I've only been using Serendipity a couple of days and I'm already very impressed with it - clean and simple, but with tons of options for customisation, and now I can even write my own plugins . Keep up the great work.