Scenario:
On registration, a special weblog entry is created which is used as the member’s profile.

Members can log into the CP to:
a) edit their profile (and no other entries),
b) Use the communicate tab,
c) Use the myaccount tab (stripped down by the lg-member-form-customiser extension and by altering cp.myaccount.php)

Question:
Is there a way to display a top navigation tab for the single weblog entry for the specific member? I can access the author_id and compare it to the member_id.

would the answer include an extension involving the cp_display_page_navigation hook?

hhmm, sounds to me like you want to give members their own pages?! profile pages?!

nah.
Ive hacked the cp.display.php file to forward the edit tab to the specific entry depending on the group_id and member_id of the logged in user. Took all of 10 minutes.