I’m using the user module, plus Leevi G’s access:restrict_to to force a custom registration (including email as username and a default password with no activation) just to capture lead data before allowing access to certain content.

Question: I am invoking {exp:user:register} for users who are not logged in/cookied, but how do I allow them to continue to the correct content (dynamically derived from various weblogs) once they have completed the form?

Are you referring to how to get the user to complete the registration form, and continue where they last left off?

I think if you leave the return parameter out, it should do that automatically… maybe not.

Otherwise, why not have the Return parameter fill up with Segment variables: