Is there any reason why you haven't updated your WordPress install? WP 2.7 was released in Dec 2008. You'll find that there are many more plugins available for more recent versions.
Have you tried searching the Wordpress Plugin Database?
If you are looking for some third party plugins then Code Canyon would be another good stop. You will note that in this link the first item which is the most popular is a navigation plugin. It is very good but may require some additional reading of steps to make it compatible with your install.