My Links in SharePoint is something that either no one uses or everyone uses; I rarely see any middle ground. In case you aren’t familiar with My Links, you get to them by clicking on the My Links link in the header of most pages in SharePoint, as highlighted below. (My Links is available in MOSS but not WSS 3.0.)
One of the confusing things about My Links is the My SharePoint Sites section. People always wonder why they see some sites they would expect and not others. Here’s how it works.
Every subsite within SharePoint has a setting for its groups. (I’m guessing that there may be some Site Templates for which this is not the case, but I haven’t run through them all.) This setting can be found by going to People and Groups, then under Settings, selecting the Set Up Groups menu option. The “Members of this Site” group is what drives the My SharePoint Sites links.
So even if you are a Site Collection Administrator for the Site Collection or a Site Owner, you may not see the site listed in your My SharePoint Sites. You *must* be a member of the Members group. To make this even more confusing, *any* group can be the Members group. You can set it to the “Billy Bob Cheerleading Society”, and only the users who are members of the “Billy Bob Cheerleading Society” group will see the site in the My SharePoint Links section of My Links.
So, if you’d like to see a site in your My SharePoint Links, talk to the Site Owner and ask them to add you to the Members group. Better yet, simply add the link to your *own* My Links by clicking on the Add to My Links menu option.
As KjellSJ pointed out in the comments below, this is yet a little more complicated.
You must be a direct member of the Members group for the site. That means that your SharePoint user identity must be a member of the group. It’s not good enough to be a member of an Active Directory group which is mapped into the SharePoint group. So it’s entirely a SharePoint group membership thing.
The Profile Synchronization timer job also has to run after you make any changes to the Members group before those users will see a change in their My Links. This is true whether you add or remove a user from the group. So it’s possible that a user may not see a site where they are a Member or still see a site where they are not.
If you’re interested in more of the internals of all of this, I just found a far more detailed post by Jerry Orman: Overview of My SharePoint Sites and how the data is populated