Give me an idea of what your site is used for and I could expound more.

One basic idea is an area where account information can be edited. You user should be able, at the very least, to change their password. Other information such as name, birth date, and other personal info. I assume you know that.

Also, most sites need people to login because they are offering certain information, so just the ability to access certain information on your site may be one thing to add. Unless you have a forum, like WebForumz. Then you would give a user the ability to post.

A little more information about your site would help.