Maybe you will find some new plugins :

1. Custom Querry String
2. Head Meta Description
3. Clean Archives
4. Exec-PHP
5. Enforce www. Preference
6. Chunk URLs
7. Sig2feed
8. FeedSmith
9. Jerome’s Keywords
10. WP-Cache

I use some of them, like for example Exec-PHP is great to exec any php code on posts or static pages. I test most of them and they are very good. I bold Enforce www. Preference because i don’t know that one and it is very simple and works.