[typo] sidebars.. how do I make one

[Ian Holsman]

Hi.
I'd like to make a sidebar to display a list of headlines which match 
the tag/category that I am currently reading.

but I have 2 questions.

1. can you make a plugin only appear when you are reading an individual 
article

2. does the plugin have access to the list of tags or the category that 
the article being displayed is in?


for an example what I want is when a user is reading

http://feh.holsman.net/articles/2005/11/20/user-registration
he will see the titles of everything else tagged with the same tags on 
the right hand side.

The aim for this is to encourage users to click on more potentially 
interesting things on my blog.

regards
Ian