1)
automatic upgrade plugin: though I was suspicious whether this would not break my wordpress, it really worked fine. It is highly recommendable, because if upgrades can be completed easily and without manual steps, you upgrade more often and things are wordpress is getting safer against latest security holes.

2)
code snippet: Here you can introduce code snippets and they are highlighted and better readable. Unfortunately it breaks html and css validation. Never the less I use it, because it is handy and writing an own code-markup plugin to ensure validation would take too long.