List all sites in web application where user has member access

I want to list all the sites in a webapplication for the user where the user is either a member or admin(not visitor).

I definitely do not want to iterate through the sites. All the other options of using SiteMap or Search will return all the sites where user have some kind of access. I am currently looking @ how membership webpart works in MySite.

Any guidance how to proceed will be helpful.

-Sharath